I'm replacing a long-broken kitchen exhaust fan which the previous owner had already disconnected from the wiring - so I can't just put the wires back the way they were as I don't know how they were. I have one romex cable coming from the wall switch, which has nothing hot, and I have one romex cable coming from an adjacent ceiling light, which is hot. I'm guessing that I must need to connect the hot wire on the fan to the hot wire on that cable, and the neutral wire on the fan to the one on the cable going to the wall switch - but I'm not sure. I also don't know what I should then do with the extra wires - the black wire from the wall switch or the white wire from the live cable, and do the ground wires from both need to be connected to the grounding screw on the exhaust fan? Any advice would be greatly appreciated.