How to Run Wiring for a Ceiling Light Box on the First Floor

Shut off all electricity to the home at the main breaker box before commencing with the wiring process.

Place a ladder under the desired location of the new light in the room where you are installing the new ceiling light box. Slide a stud finder across the ceiling to locate the ceiling joists. When the stud finder lights up and stays lit, you have found the direction of the joist. Mark it with a pencil and then locate the joist nearest to it so you can run the wiring through it.

Climb the ladder and hold the new light box against the ceiling with one hand. Trace around the perimeter of the light box using a pencil.

Set the light box aside and cut the outline out of the ceiling using a drywall saw or a keyhole saw if the ceiling has wooden lathe behind it. Wear safety glasses for protection when cutting through the ceiling.

Move the ladder to the location where you are running the electrical wires. If you are connecting the light box to an existing light, place the ladder next to the light. If you are running the wires from the electrical box, move the ladder to the side wall closest to where the wires run through it.

Cut a 3-by-5-inch hole in the ceiling next to the light or in the ceiling next to the top of the wall closest to the electrical box. Use the same cutting technique used with the first hole. If you are threading the wiring up from a wall or next to a ceiling joist, cut the hole at the top of the wall. Then, create a 1/2-inch wide and 1/2-inch deep notch in the stud or joist using a hammer and chisel.

Move back to the first location and insert the wire from a fish tape into the hole. Push the wire through the ceiling cavity until it reaches the other hole. It helps greatly to have another person assist with this while they stand on another ladder.

Ask your assistant to grasp the end of the tape and clamp it onto the wire you need to thread through the ceiling. Wind in the reel of the fish tape to pull the wire through the ceiling until you see it emerge from the new ceiling hole. Have your assistant guide the wire through the notches in the wood studs or joists as necessary.

Unhook the clamp from the fish tape and finish installing the light box per the manufacturer’s instructions.