Quirky one I would have never thought of had I not encountered it: can the electricity stay on while you are out of the room? So you can charge things, eg.
Place I stayed at this year had the key card act as a switch for the power. You came in, put the key card in the slot, and you could turn things (including lights) on. Remove the card, it all shuts down.
Perhaps needless to say, there was no in-room fridge.