All light fixtures have a universally-sized, pre-wired box in the ceiling, which the three electrical wires descend from. There will be some sort of baseplate serving as the mounting hardware for your light fixture. It’s either a single bar “strap” with a “nipple” screw (I hear you...
Turn off the breaker that controls the fan circuit in the home's main service panel (breaker box). Unscrew the cover from the electrical box that contains the fan wiring using a Phillips screwdriver and then remove the box cover. Test for power with a noncontact voltage tester, touching the...
Another option (if your inspector allows it) is to wire on a cord and simply plug the furnace into a nearby electrical outlet. This is simpler, and allows you to plug the furnace into a backup power source (generator or large battery) to restore heating in the event of a power failure...
The junction box is a round, square, or octagonal box, usually made of plastic, in the ceiling under where the fixture used to be. As Hornof points out, there will almost always be a white wire for negative and a black wire for positive. You can simply disconnect the black and white...