But I do believe people who say they've been visited by ghosts, and I love to study ghostly pictures of these close encounters.
The trouble is that so many are obvious fakes. People have been making ghostly double images to fool their friends since cameras were first invented.
But these 13 photos have never been explained.
Maybe they show ghostly encounters, or maybe not. But there's no denying they're chilling.
1. Lord Combermere's Ghost
Look in the chair on the left side of this photo to see one of the most famous ghostly apparitions ever photographed.
This picture of Lord Combermere's library was taken during his funeral in 1891. But the lord can clearly be seen sitting in his favorite chair.
Lord Combermere's own children agreed the ghost looks just like him. The only thing missing are his legs - which were badly damaged in the carriage accident that killed him.
2. The Ghost Of Bachelor's Grove
The Bachelor's Grove Cemetery outside of Chicago is known as one of America's most haunted burial grounds.
Visitors have recorded seeing ghosts, taking eerie pictures, and even recording strange sounds.
The cemetery's most famous spirit is the white madonna, who is said to wander the grounds every full moon.
But in 1997 the Chicago Sun-Times took a photo of the empty grounds and captured this woman in an old-fashioned white robe.
3. The Amityville Horror
The horrifying events that took place at the infamous home on Ocean Avenue inspired a bestselling book and a number of hit movies.
But when paranormal investigators Ed and Lorraine Warren dug into the case, they had a real reason to be scared.
A camera left overnight in the house captured this still, which is said to show the ghost of young John deFeo, one of the haunted home's victims.
4. A Family Photo
Reddit user Njfurlong shared this eerie photo from his family album, which he says was taken around 1930.
Look at the door frame just above the group to see the spirit that supposedly lived in the home.
"My aunt saw her a few times while growing there in the '60s and '70s," he wrote.
"[Always] beside or at the end of her bed. She wore a fitted white bodice-style dress, with a dark brooch at her waist, dark hair up in a bun.”
5. The Shining
The Mausling family were visiting the Stanley Hotel, the creepy inspiration for Stephen King's horror novel The Shining, when John "Jay" Mausling took this photo.
"At first we tried to be logical and think we somehow missed her so we asked our kids, their girlfriends and our friend if they remembered seeing a little girl," he said.
But there was simply no little girl on the tour.
A former FBI agent told HuffPost that he couldn't find any signs of trickery in the picture.
And this isn't the first sighting at the Stanley Hotel either:
Henry Yau captured what looks to be a woman in an vintage dress descending the deserted staircase.
6. The Brown Lady
This picture, one of the most famous ghost photos of all time, was taken by photographers for Country Life magazine in 1936.
The cameraman's assistant described seeing a woman in a veil stepping down the staircase, and said he urged the cameraman to take a photo. She vanished just after it was taken.
The woman in the photo is believed to be the spirit of Lady Dorothy Townsend, who died of smallpox in 1726.
No one knows what drives the Brown Lady to return to her home after death, but she's been spotted regularly since then.
7. The Schoolboy
Reddit user Inthelionsmane offers this spooky description of a famous ghost picture from his hometown:
"I grew up in a small, rural town in between mountains.
A couple of years ago, they were tearing down an old elementary school. A guy my mom knew went in and took pics with his cell phone. When he uploaded them, this was one of the pics.
I don't believe in stuff like this at all. I just really don't know how to explain it since it was a cell phone pic and I'm pretty sure that no one in my Podunk hometown knows how to make fake pics."
8. The White Lady Of Worstead
Diane Berthelot stopped to pray at the Worstead Church in Norfolk, England, and her husband Peter snapped a souvenir photo.
But they were both stunned to see a glowing, white ghost sitting in the pew behind her.
After showing the photo to the church vicar, he revealed many visitors have glimpsed the white lady, and say she's a friendly, healing spirit.
9. The Tulip Staircase Ghost
Reverend Ralph Hardy was trying to take a photo of a famous staircase in the Queen's House, in Greenwich, England. Instead, he caught a ghost on film.
The reverend insisted that no one had been standing at the foot of the stairs when he took the photo.
Experts from the era, including from the Kodak film company, could not find evidence the photo was tampered with.
10. The Grandfather's Ghost
There's a simple but spooky problem with Denise Russell's photo of her grandmother.
It was taken in 1997, but the man in the background looks just like her grandfather. The trouble is he died in 1984.
Maybe he just came back for one last visit, and even stopped for a souvenir photo.
11. Ferguson's Brother
A guest at a spiritualist convention snapped this picture of speaker Robert A. Ferguson, and maybe his brother Walter too.
The ghostly image behind Ferguson is said to be a dead ringer for Walter, who was supposedly killed in World War 2.
It's hard to chalk the picture up as a double exposure, because it was taken with a Polaroid camera.
12. Freddy Jackson's Last Photo
The supernatural story behind this photo comes courtesy of Royal Air Force officer Victor Goddard.
Even though he died before the group picture at the HMS Daedalus training grounds was taken, Goddard swears the man in the last row is the late mechanic Freddy Jackson.
Skeptics have investigated the photo, but still have not disproved the ghost sighting.
13. The Corroboree Rock Watcher
The reverend who took this photo insisted he was alone at the rock formation, and said the figure in a white gown only appeared afterwards.
Along with debating whether or not the ghost is real, there's a question of just who is in the photo.
Some day it's a priest, while others argue it must be an aboriginal woman, because Corroboree Rock is a sacred place to Australia's native population.
And a mother says this picture shows a ghost haunting her daughter.