For some background knowledge, my father built our house a year or two before my experience. I was either 7 or 8, don't remember exactly. At my age, I hadn't had any family die to even begin to comprehend or think about the after life.
Looking back, I think it's interesting that the house was new and still having spirits entering or leaving, doing whatever "it" was doing. As a child I had a bunk bed that my great grand father had built for me. One night I suddenly woke facing the wall, not sure what had woken me up, and I just laid there for a few seconds and then felt a heavy presence in the room.
I actually thought my mom or dad might have been in the room checking on me. I said out loud "hey" as I rolled over to look over my bed. A man was standing there by my bed at about my eye level since it was a bunk bed. He was just staring intently and for a split second I thought it was my dad. I realized in a split second it wasn't my father and his look changed from intently to almost an evil/sadistic grin.
It looked as though his fists were clenched at his sides like there was something in his hands but I couldn't make it out. He looked real but at the same time not and had a greenish dull hazy tint. I didn't notice what he was wearing as he was just dull. This thought process of analyzing this man happened in maybe a second or two. I yanked my covers over my head and laid there in paralyzed fear unable to scream or move. I ever so slightly and slowly turned over towards the wall again and just laid there my heart pounding so loudly that was all I could hear.
I KNEW I had been completely awake as I was now thinking about what happened and I couldn't comprehend it. I wanted to scream for my mom but I couldn't. Something in me said "don't make him mad by getting your mom". I wanted to pretend it was a dream and that way it wasn't real and he couldn't hurt me. Either way, I didn't tell my parents about it until years later when I was a teenager and we were talking about ghosts one morning at breakfast.
Throughout my years living in my parent's house I had a few other random experiences at night like waking up in paralyzed fear feeling a presence in the room and sleeping with the light on. I would have fits of nightmares where I felt like I was almost not in control of myself and I couldn't wake up even though I was aware I was dreaming and trying to wake up.
I had many feelings over the years where I felt someone was watching me, especially in the shower and the hairs on the back of my neck would stand up. Either way, I see all of these smaller experiences as they could be whatever but I'm sure of my experience as a child. I certainly don't wish for it to happen again and it truly was one of the most frightening moments of my life. Still makes my heart and mind race thinking about it today.
Being in a semi-dream awake environment allows us to view a different scene.
We may be more open to other things that our rational mind cannot comprehend. If you are a sensitive, or very in touch with emotions, then perhaps these energies can sense that and make their presence known.
It could be possible that Sleep Paralysis and the ability to interact with spirits go hand in hand. Once the door is open, we cannot necessarily pick and choose who comes through that door, unless we are experienced, and few people are.
Take Care.