Is there a ghost in my room?

Okay, so every once in a while when I am in my room alone, the keyboard piano started making all these clicking noises. I don't know why. . . I thought once it was just the floorboards because i was stepping near it, but it happens when i am not standing next to it at all. its not plugged in either so it can't be electrical currents or anything. it sounds like someone is pressing on the keys a bunch. is there any logical explanation for this? Please help. I'm kinda freaked out by this.