The magical stalking sanding ghost

Someone either upstairs or next door or in the hall is sanding or doing something that makes a lot of scrapey and frictiony noises. The weird thing is that no matter where I am in my apartment, this noise sounds like it's coming from the nearest wall or ceiling. As I lay in bed, it sounded like it was coming from the ceiling directly above me. Then as I sat in the toilet, it sounded like it was coming from the wall of the apartment next door. Then as I wandered into the kitchen it sounded like it was coming from the hall. Now I'm in the living room, and it sounds like it's coming from a different part of the ceiling.