Rental house? I highly suggest you check out the clothes dryer (if it has one) and the vent pipe. I did that in a rental house once, and freaked out at the condition I found the shit in. It was ready to go up at any moment. The handle of the lint screen was broken, so the other tenants never cleaned the lint trap out. Blew my mind how much crap I cleaned out of the whole thing, and there was already paint burnt off part of the dryer, it had gotten so hot.