I hear a loud bang as if from another room. Like a trash can falling over, or a someone dropping a bag with about 10lbs on a hardwood floor, or a pushing a wooden chair into a dining table too hard. It's enough to think "what just fell?!".
It does not sound like a door closing, or stomping, or something fragile moving or falling.
I startle awake, realize I'm the only one awake, and that there aren't anymore sounds so it must have been my brain and I pass out fully.
It's pretty strange and I think it's funny how I never really thought about it until now.
Have you seen the housing market? Sometimes you have to deal with a roommates bad habits, even if he is a spirit.
At least he doesn't leave dishes in the sink.