Halloween is my favorite time of year, but I never need an excuse to turn off the lights and watch a scary movie.
Of course, I get a little freaked out afterwards. It can help to remind myself, "It's only a movie," but that's not always true.
These 13 horror movies have terrifying inspirations that are very real. So watch these movies with the lights on.
1. The Amityville Horror
The line between fact and fiction is blurred in the books and films inspired by the real crimes that took place at 112 Ocean Avenue in Amityville, New York.
In 1974, Ronald DeFeo Jr. murdered his father, mother, two brothers and two sisters while living in the home.
Just over a year later, George and Kathy Lutz moved their three children into the home. But after less than a month, the Lutz family would move out, claiming they were haunted by paranormal activity during their short stay.
The family felt themselves being hit by unseen presences, heard voices telling them "Get out!" and suffered strange illnesses while living in the house.
The most terrifying experience came at 3:15 a.m. each night (around the time of the DeFeo murders) when George could hear his children's beds "slamming up and down on the floor."
The last straw for George was when he awoke one night and found Kathy levitating above his bed.
The next day, the family left in a rush, leaving behind their clothes and even the food in their refrigerator.
Only the Lutz family can say for sure what they saw in that house, but it scared the daylights out of them.
2. Nightmare On Elm Street
In the Nightmare series, the disfigured baddie Freddie Krueger chases the teenagers of Elm Street through their dreams.
Anyone Krueger catches and kills in the dream world also dies in real life.
Director Wes Craven revealed the chilling real-life inspiration for his classic films: a Los Angeles Times article about a young Cambodian refugee.
The boy reportedly stayed awake for days because "he was afraid that if he slept, the thing chasing him would get him."
"When he finally fell asleep, his parents thought the crisis was over," Craven remembered. "Then they heard screams in the middle of the night. By the time they got to him, he was dead. He died in the middle of a nightmare."
Similar cases of refugee men dying in their sleep were also reported, and it was dubbed "sudden unexplained death syndrome" or "Brugada syndrome" by medical authorities.
Like in Craven's movie, the boys parents reportedly refused to believe he was terrorized by his dreams, until it was too late.
In the classic horror film Poltergeist, a home possessed by malevolent ghosts is plagued by dark visions and unexplained events, before the family's young daughter is sucked into a TV.
A real family, the Hermanns of Seaford, New York, lived through an actual poltergeist haunting in the late 1950s that inspired the movie.
"I never saw Poltergeist," Lucille Hermann told HuffPost. And she was never sucked into a television either. But she lived through a serious and unexplained haunting.
"All of a sudden, you'd hear this loud noise, like a popping bottle sound, and you'd look around and find a bottle that was 12 feet away from where it was supposed to be and all the contents were missing and the bottle was hot to the touch," she remembered.
The case eventually made the cover of Life, and the widespread coverage popularized the term for a noisy ghost that knocks things over - a poltergeist.
But the cause of the haunting was never solved. The Hermann's eventually just moved away, but there's no telling if the ghost did.
This twist on the classic slasher flick gave the genre a funny twist, but the real crimes that inspired Scream were nothing to joke about.
A real serial murdered nicknamed the Gainesville Ripper killed five students from Florida with a knife in just a matter of days.
It took months for police to identify burglar Danny Rolling as the killer, and his court case attracted plenty of attention, as Rolling broke into song throughout the trial and blamed his crimes on an alter ego named "Gemini."
The real Ghostface killer was finally executed in 2006, while the series he inspired continues to this day.
5. The Conjuring and Annabelle series
In each installment of the popular Conjuring series, paranormal investigators Ed and Lorraine Warren help a family haunted by evil spirits.
But fans may be surprised to learn that the Warrens - and the cases they investigate - are real.
Lorraine served as a consultant on the first film, and the hauntings featured in both The Conjuring and The Conjuring 2 are straight out of her case files.
"The things that went on there were just so incredibly frightening," she told USA Today about her work. "It still affects me to talk about it today."
One of the real children from the Perron family, featured in the first movie, also recalled seeing her mother possessed by an evil spirit in an interview about the film.
"I thought I was going to pass out," Andrea Perron said.
"My mother began to speak a language not of this world in a voice not her own. Her chair levitated and she was thrown across the room."
But the Warrens played a part in a number of other classic horror stories too, like when they investigated the Amityville haunting.
Annabelle, the haunted doll who was given her own spin-off series of movies, also has an origin story connected to the real life Warrens.
The pair say a Raggedy Ann doll they investigated would move on its own, and sometimes wrote notes with bizarre messages like, "Help us." Just like in the movies, a medium determined that the doll was possessed by the spirit of a deceased seven-year-old girl named Annabelle.
6. The Exorcist
A Halloween favorite, this movie has been scaring audiences silly since 1973.
But the story that inspired the film, about a possessed little boy, dates back to 1949.
The Washington Post reported that a boy from Mt. Rainier, Maryland had been freed from the "Devil's Grip" by an exorcist, and the story stuck in director William Friedkin's mind.
"Maybe one day they'll discover the cause of what happened to that young man," he told Time Out, "but back then, it was only curable by exorcism."
Friedkin said reading the real life horror story convinced him there had to be a kernel of truth to many stories about possession and exorcism.
"The Washington Post article says that the boy was possessed and exorcised," he remembered.
"That's pretty out on a limb for a national newspaper to put on its front page... You're not going to see that on the front page of an intelligent newspaper unless there's something there."
"Roland Doe," the boy whose exorcism was featured in the news story, never publicly discussed his case, so we may never know what really happened to him.
7. Child's Play (the Chucky series)
There's no shortage of haunted or possessed dolls in movies (take Annabelle for example), but Chucky is the most famous and popular of them all.
But even he doesn't hold a candle to his inspiration, Robert, an infamous and real haunted doll owned by author Eugene Otto.
The 104-year-old doll, originally owned by Otto's grandfather, is dressed in Otto's own childhood sailor outfit.
It lived with him for many years, and remained in the property when it was turned into a guest home after Otto and his wife died.
So what's so scary about him? Countless people say Otto can move on his own, change facial expressions, and will even giggle.
The doll, who lives in a pair of museums in Key West, Florida, has been blamed for causing "car accidents, broken bones, job loss, divorce and a cornucopia of other misfortunes" against anyone who disrespects him.
So let me just say, he looks dashing in that sailor outfit.
8. The Possession
In The Possession, a mysterious wooden box discovered at a yard sale causes a teenage girl to display strange behavior, and a spirit inhabiting the box eventually kills several people.
While it sounds unbelievable, antique buyer Kevin Mannis complained he was haunted by just such a wooden box, and his real life story inspired the movie.
Mannis called his box a "dybbuk box," and claimed it was inhabited by an evil spirit from Jewish folklore.
He claimed that after giving the box to his mother as a birthday present, she suffered a stroke. Mannis also claimed that after sleeping in a home with the box, three of his friends experienced the exact same nightmare at once.
He put the box up for sale on eBay, and since then other owners of the haunted box have claimed that it caused strange things to happen to them.
The box may have haunted the movie's production too: director Ole Nornedal claimed an unlit neon light exploded over him on set, and that the film's props were destroyed in a fire five days after filming wrapped.
"I'm not a superstitious man," he said, "and I would like to say, 'Yeah, it's just a coincidence.'"
9. Deliver Us From Evil
In the 2014 film, a police officer and a priest join forces to investigate a series of crimes connected to the supernatural.
While it sounds like fiction, the movie was inspired by retired NYPD sergeant and self-described "demonologist" Ralph Sarchie's life story.
The former cop claims he regularly performed exorcisms and battled demons while patrolling the South Bronx, and described some of his most hair-raising cases in the book Beware the Night.
If you want to dive deeper into the disturbing unexplained cases featured in the movie, Sarchie's book is a good place to start.
10. The Ed Gein Connection (Psycho, The Texas Chainsaw Massacre, The Silence of the Lambs, and more)
No single person has inspired as many creepy movies as serial killer Ed Gein, and for good reason.
Gein was a murderer and grave robber infamous for turning dead bodies into disgusting mementos.
Investigators discovered a wastebaskets, chairs, bowls, a corset, leggings, masks, a lampshade, and a belt all made from human flesh in Gein's home, along with other stolen body parts.
While Gein's revolting hobby inspired The Texas Chainsaw Massacre and The Silence of the Lambs, his obsessive fixation with his own mother inspired the character Norman Bates from Psycho.
Investigators believe Gein targeted graves of women who looked like his mother, and also tried to build a "woman suit" resembling her from stolen remains.
11. The Exorcism of Emily Rose
This modern take on exorcisms creeped out audiences with the story of a young girl who died as a result of the ritual.
But, sadly, this story is all too true.
A German woman name Anneliese Michel reported hearing voices and reacted strangely to religious objects.
Eventually, she became suicidal. Michel and her family, believing she was possessed by demons, convinced a pair of priests to perform an exorcism on her.
But after being deprived of food and water during dozens of rituals, Michel died.
Her symptoms were later blamed on epileptic psychosis - not demons - and both her parents and the priests were later found guilty of negligent homicide.
So it was a real life horror story - but not the kind you see in the movie.
If you saw this recent film and wondered how they built the enormous haunted house full of twisting hallways and stairways to nowhere, we have bad news.
The Winchester mansion is a real 160-room mansion in San Jose, California, and often listed as "America's most haunted home."
The house was built in the 19th century by Sarah Winchester (played by Helen Mirren) but the reasons behind her endless renovations are still unknown.
The most popular theory is that Winchester was haunted by ghosts of her family's rifle business, but it's unclear if her home's crazy architecture is meant to confuse ghosts, or was inspired by their instructions.
What we do know is Winchester was a strong believer in the supernatural, and often held seances in a special room of the house.
If you're brave enough, you can explore Winchester Mystery House yourself.
13. When A Stranger Calls
This surprisingly popular urban legend has inspired a number of movies, but the When a Stranger Calls films are the most well-known.
A young girl working as a babysitter is terrorized by eerie phone calls asking if she has checked on the children sleeping upstairs.
Eventually, police manage to trace the calls and make the chilling discovery that they came from inside the house.
Janett Christman, a 13-year-old babysitter who was murdered at a client's home in 1950, offered the disturbing real life inspiration for the legends and films.
Before being killed, the teenager from Columbia, Missouri called police and screamed "Come quick!"
The parents she was babysitting for came home that night to find Christman in a pool of her own blood.
In a chilling twist, Christman's murder is still unsolved to this day. Although, police have a working theory that someone who knew the house (and Christman) convinced her to let him in, before framing the crime as a break-in.