I should start by saying that I have experienced sleep paralysis before and although I believe it is a real, physical experience, I also hold the belief that sleep paralysis is caused by the paranormal.
My husband worked on a crew away from home the year I was pregnant with my son. He was there for three weeks at a time and then came home for a week. The town was a four hour drive from where we lived, so it made sense that he would rent a house there.
A bunch of guys on his crew decided to rent a house together to save money. They found an old farmhouse to rent. The house was a beautiful, two story home with high ceilings and a small balcony off one of the upstairs bedrooms. But it was quite old. I imagine it was built somewhere in the pre-depression period, but can't be sure.
Because my husband was away for so long, I would come to visit him at the house quite often. Three other guys had bedrooms upstairs, but my husband had offered to take the bedroom just off the kitchen. The first time I visited, my husband showed me his bedroom. It was terribly creepy, having no windows and something in the wall that looked like it had been the opening to a crawl space that had been walled over. I also noticed a quartz crystal hung over the door by a piece of ribbon. I showed my husband the crystal and he hadn't even noticed it up to that point and started to remove it. I stopped him and told him I liked it so he would keep it up.
For those who are unaware of crystals, a lot of them are meant to absorb negative energy and ward off evil spirits, especially quartz. It is said, when a crystal has been saturated with negative energy, it becomes clouded over. This crystal was completely clouded. When my husband went to work, I removed the crystal and put it in some salt water in the sunshine, which is meant to remove the negative energy. When I removed the crystal hours later, it was clear. I rehung it above the door and checked it hours later to discover it was clouded over again. This means, more negative energy was caught.
I spent many hours alone in that house, just waiting for my husband and his crew to come home from work. I baked for them and cleaned and made supper. But every day, I could hear footsteps and furniture being moved around upstairs. Things would disappear and reappear in strange places. And I heard, what sounded to me, like a tennis ball being dropped from a distance and allowed to bounce along the floor. My husband tried to explain it was the furnace, but the sounds continued well into the summer.
One night we were sharing our experiences in the house and one guy, who was actually pretty quiet and serious, said matter-of-factly that the house was haunted by a dog. We all kind of laughed, but he was dead serious. He said in the early morning hours he could hear a dog panting and whining near his head and then could feel something lay on the end of the bed. He could actually feel dog paws slung over his legs at this time, but when he looked, nothing was there. He also said on numerous occasions he felt a dog licking his hand as it was slung over the edge of the bed. He also said he could hear the dog playing with a ball and dropping it at his feet and allowing the ball to bounce until it stopped on the ground near his feet, but he couldn't see a ball or a dog. I assumed this was the ball bouncing I had heard as well.
The other guys told similar stories about hearing footsteps and furniture moving upstairs, but when they looked, nothing was out of place. They also said they were missing items that showed up in the weirdest places as well.
One day, as the job my husband's crew was working on was nearing an end and the homeowner was showing the house to potential buyers or renters, I woke up to an empty house, but began to hear voices. The voices sounded like they were coming from outside and I thought the homeowner must be showing the house today. I started to get up to shut the bedroom door so I could get dressed before they came inside, but I couldn't move. I could only move my eyes. I kept hearing the voices, but it started to sound like they were outside and then right beside me and then upstairs within seconds of each other. I started to see black figures in the room with me, so I closed my eyes. A hand closed around my neck and I couldn't breath. I could feel something sitting on my chest. It lasted a few minutes and suddenly, it ended as quickly as it began. I sat up drawing in a deep breath, like I had just been held under water for a long time.
I rushed out of the house and refused to come back until my husband came home from work. I never did get a lot of information on the house, but it sounded like everyone in the small town knew it was haunted.
I truly believe that whatever paranormal entity was in that house is what caused my sleep paralysis. And from every other story I have read about sleep paralysis, it sounds like paranormal activity has lead up to the event in most cases. Since I was pregnant at the time, it was one of the scariest things that has ever happened to me as I feared for myself and my unborn son.