This first part is a bit of background. You may skip ahead if you really wish.
Around 13 to 14 years ago, (I was five or six then) my mother, her boyfriend, and I moved from one trailer to another. The new one was still in the same area, in fact, it was only about 100 to 150 feet away, diagonally.
It was a small area. There were only seven trailers and two houses in the area. The furthest of the nine was only a 5-minute walk. There was a third house further up, but that was about a mile up the lane. It dead-ended at an older woman's house.
Anyways, the trailer was not very big. The main door opened to the living room, to the right was the kitchen and to the left, at the far right, was a hallway. In the hallway, there are three doors on the left, one at the end of the hallway and one on the right that led outside to the back yard. My room was the second door on the left.
The Incident--
I was 5 or 6 when the incident happened. Earlier that day my friend, Whitney, had been over and we had been playing and a while later she had to go home. The details are somewhat sketchy about what I had been doing prior to what happened (I was most likely playing with dolls or something), but something caused me to look up and into the hallway. (I had the door open so from where I was, I could see into the hallway clearly.) The instant I looked up a figure went past my doorway (whether it was walking or running I do not remember) I instantly said "Whitney?" and got up and went to the doorway and looked left. No one was there. It was then that I remembered that my friend had already gone home a little bit ago. I never thought anything of it at that age... I was confused though.
I still, to this day, do not know what made me look up or what made me instantly think it was my friend, who I watched go by the doorway. I think I thought it was my friend though because it looked like her, shadowed, but it had to of looked like her... I do not think I would have said her name otherwise.
I do know that no one else saw "her" even though mum and her boyfriend were like 20 feet away in the living room (where the hallway began.) I never told anyone about it until years later. When I found this site, I thought that someone might be able to give me an idea about what I saw... It still kind of bothers me to this day since I really have no explanation for what I saw then.
What you described is similar. Some sort of spirit. I don't think anyone can tell you anymore except God himself, or the spirit who did it.