As you had probably guessed (by the “fiction” tag), the story I wrote a while back, It Only Takes Once is fiction. However, as I mentioned in the comments, it does take place in the apartment I’m currently living in. As I sit at my computer, I can look into the bathroom and see the window where the hand appeared. This one:
The following is true, by the way. Just so there’s no confusion. A few minutes ago, as I was sitting at my computer, alone in the dark, the light went on in the hall. The motion-sensor light. I suddenly heard this “squeak, squeak, squeak” over the sound of my music and I looked into the bathroom. Through the frosted glass window I could see my neighbor’s door moving back and forth really fast. Maybe it was just sitting in the dark alone like this, but it reminded me of the rapid, jerky movement of the haunted rocking chair in the movie The Woman in Black.
After about 20 seconds, the door slowly closed and the light went off. I’m sure there is a perfectly natural explanation for it all, but it made me really excited, because what if there wasn’t?