Just a short one here - I moved with my family to a new home in the city when I was 12. I lived in that house until I was 19. Several, countless times over those years, I would see something out of the corner of my eye while sitting in the living room. It always seemed to be something high off the floor, like chest to head level on a tall man, moving from left to right down the hallway that all of the bedrooms came off of. My bedroom was to the right, the only room on that side. I always found it strange because it had no form in my vision, it was just a 'shape', like catching the shadow from something... but there are no windows in that hall and the bedroom windows are in various places, but this would happen at night as well as during the day. I could never figure it out. I only knew that it bothered me when it kept happening, because whatever it was moved toward MY bedroom. The only other doorway there was the ceiling hole that went into the attic, right outside my bedroom door. Either way - attic or my bedroom, I didn't like it, but could never make sense of it or catch it in my full vision.
I am now almost 40 and less than a decade ago, my younger brother and I were chatting and somehow got to talking about strange events, or ghost stories. He floored me by saying that something in our old house used to bother him... and then he went on to explain seeing 'something' move down the bedroom hallway, always out of the corner of his eye. I could not believe my ears! I said 'What direction was it going in?' and he was uncomfortable but said 'always toward where your door was'. I told him that I saw the same thing for YEARS and he was shocked. He is 6 years younger than me, and lived in that house until he was 18 (when I was 24), and he said he doesnt seem to recall seeing it when he was a little kid, but did when he was a teen.
So I don't know what it was, it was just nice to have the story matched by another person, so I didn't feel quite so insane :) He said it was like a shadow, up high, and moving fast. Same as me. Very odd. Mom sold that house around 2003. I would love to know if other people experienced it, but I most likely never will.