Ghosts

Again last night I heard unidentifiable noises. Somewhat melodic and fairly redundant, the best I can describe them as is like a radio that you can just barely hear. And they sounded like they were coming from the wall.

I opened the window and stuck my head outside. No noise.

In the basement directly under the bedroom I couldn't hear the noise.

I'm stumped. Ghosts? Vermin gamelan?

The noise stopped around 2AM.