Short for ampere, a unit of measure for current or the volume of electricity running through a circuit. The amp rating for a device or cable determines the amount of current it can safely handle. Typical household circuits begin at 15 amps and go up to 50 or 60 amps.
Insert a clamp, with wires attached, into the junction box hole and from inside the box, push the included nut over the wires and onto the clamp threads. Turn the nut as far as possible onto the threads and then use a screwdriver and hammer to tap it down until it’s tight.
Also called an old-work box, these are electrical boxes with built-in clamps to fasten them into finished walls. All that is needed to install one is to cut a hole the proper size in the hollow part of a wall and insert the box. These can be used in drywall, plaster or paneling. They are best suited for adding wall receptacles and switches. Because they don’t offer much support, old work boxes are not a good choice for installing a new ceiling fixture.
Shut off the electricity at the service panel for the circuit you will be working on. Test the circuit using a known working lamp or other electrical device to be sure it’s off. Flip a light switch to be sure the bulb doesn’t light, or use a volt meter to test the wires and confirm the circuit is off. Remove the cover plate and the top and bottom screws holding the mounting strap to the outlet box. These are long screws and easier to remove with a drill-driver if you have one.