When I was about 11, we were living on an old Army base near Highland Park, Illinois named Fort Sheridan. The base was established in the 1800s, so most of it was pretty old. Lots of weird stories about it, from a long-dead Chaplain appearing in a photo taken during Christmastime of an empty street to a phantom horse that you could hear and feel rush by you at night by the south gate. The library had been an old hospital during the WW2 era, and the one-room morgue still sat locked up in what became the parking lot. Here's a photo of it before they built the parking lot around it. It was referred to as the "Dead House".
The basement was where they kept the terminally ill and the dying, but after it was converted to a library it was used as storage and the windows were painted black and boarded over. At night, though, you could still see white ovals peeking out of the windows, as if those who had died down there were trying to look out. I saw them myself and even went face-to-face with a few, trying to figure out if it was an optical illusion or a trick of the light, but I could never figure it out.
Now for my personal story.
We lived on the south edge of the base on the shore of Lake Michigan that backed up to a wooded area in a two-story home reserved for enlisted families. They were multi-family units, usually four units to a building laid out individually like townhomes. My bedroom was upstairs and my window faced out into the woods.
We had taken in my stepdad's grandmother, who was in her late '80s and basically bedridden, until we could find a nursing home she wouldn't get herself kicked out of because she was an ornery, mean woman. I had moved into my brother's room next to mine so she could sleep in my room for the time being. Granny had a habit of waking up in the middle of the night and calling for anyone who would wake up to come check on her, because she wanted to make sure that if she was up, no one else was sleeping. We eventually simply began to ignore her most nights because we knew she was just wanting attention.
One night, she sounded different. Scared. My stepdad and I went in to check on her and she said she had seen something in the doorway. A tall, slender woman in a black dress with a white lace collar that had walked into the door and disappeared through the wall that faced the woods outside. We figured that Granny had gotten wise to us ignoring her and decided to make up a story to explain why she was hollering in the middle of the night. She kept on for the next few weeks until we found a nursing home for her and I got my room back.
I've always been a pretty deep sleeper, not easily woken up by anything. Even slept through an earthquake when we were living in California. About two weeks after Granny left, I woke up in the middle of the night and turned over on my side, facing the doorway. In the doorway was a tall, slender woman in a black dress with a white lace collar. She began to walk through my room and disappeared through the wall that faced the woods outside. I pulled the covers over my head and froze for what seemed like hours until I finally fell back asleep somehow. I told my stepdad the next morning that maybe Granny wasn't making stuff up after all and relayed what I had seen the night before. He just shrugged and said her story probably stuck in my head and I hallucinated it when I was half asleep, which wasn't unreasonable.
We lived there for 3 more years until we moved to California in '94, and over the course of those three years I saw her again at least a dozen times. Eventually I figured it was just some sort of replay or a glimpse into the past that somehow can happen if conditions are right, since she never seemed to even know I was there and stuck to the same routine every time.
That sparked a life-long interest in the paranormal, though the more and more I look into it the less I believe in anything supernatural. I just think there are parts of the natural universe we simply don't understand or know about that to us seem supernatural.