This is something that happened 8 years ago. I haven't thought much about it, until recently that I read someone posting a question regarding a knocking ghost on answer.yahoo.com.
Anyway, I was living alone in a small studio in Falls Church, Virginia. I may have been living there for some months (probably weeks), when I started to notice some sort of noises coming from the ceiling in the middle of the night. That may not have been a problem, except that I was living on the 3rd floor, and above me was the roof. As for the noise, it was like some scratching, and even a knocking sound. I am not very good at locating sound, but I was pretty sure that it came from the studio corner, up in the wall toward the ceiling, just above my bed (and my head). It would just wake me up. I would turn up the lights to see where the sound was coming from, and it would temporarily stop. After I'd turn the lights off, it would resume after a while.
I tried to convince myself that it was some chipmunks, or other kind of animals making that noise... Although, what animal would be up in the middle of the night making that?
Other than that, I have never felt any kind of weird thing going on in that studio. However, I had never been very comfortable living there either. Probably I was also lonely and homesick (I was a foreign student working on a Master degree). I remember going to the bathroom at night, and walking directly to the toilet trying not to look at anything else (like the closet, the bathtub, and especially not to look at the bathroom mirror).
I remember the noise would come and go. One day I got pretty uncomfortable, and decided to get a pet for companion. I got a ferret from a pet store. A week later, some neighbour kids found some stray kittens, and I took a black one with me. I think since then, I stopped hearing the noises. I also felt more comfortable with the cat around me.
Anyway, would that be a spirit trying to call me? Did my black cat get rid of the spirit? Or anyone know of an animal that would make knocking sound on house roofs (or walls), in the middle of the night?