I'm going to give a bit of background info on what room I was in, and how I can try to figure what went on. The computer is located in the computer room. This happened when we had the old computer, one that wasn't exactly the brightest, but it could still cause shadows when one walked by. The computer is located near a window, which you can see the road from. When cars drive by at night, you can see the lights reflecting on the walls, and they travel across before they vanish.
I was sitting in my computer chair, talking to a friend online, with my cat sitting behind me on a chair. I was bored, and I kept swaying back and forth in the spinning-computer chair, watching my shadow behind me while waiting for my friend to reply to what I sent. It was quiet, and no one in the house was up, because my brother was in his room, snoring (loudly I might add) and my mum was upstairs, and if she were to come down, I would hear the stairs creak.
Well, I turned back to the computer to look at what my friend had just said, when I heard a noise. I couldn't really tell what it was, it just sounded odd, so I turned to look at Autumn (my cat), who was staring at the doorway leading into the living room. I looked up, just in time to see a black haze, that looked at if someone were standing, before it vanished. My cat jumped off the chair to go into the living room, so I got up to follow, to see if my dog was up, or if my brother had come out of his room. When I stood in the door frame, I didn't see anything, other than my dog sleeping under one of the tables.
I don't know what I saw, but it freaked me out quite a bit. Of course, I don't fuss about it anymore. But I thought I'd tell the story.
Oh, and this happened at the beginning of December, 2006. I was fourteen then, and I am still that age now. So it wasn't to long ago.
And, you can believe this if you'd like, or not. One possibility is that my eyes were playing tricks on me, because it was really late into the night. Actually... it'd be extremely early the next morning. Around 3:30 AM. But, I'm still unsure, whether it was paranormal or not, I do not fuss.
I know there are spirits in my house, but they do not bother anyone.