How to Install Wiring Behind Drywall

Mark the location of the wiring's junction box you want to install by tracing the box's outline on the drywall with a pencil. Use a ruler for increased accuracy.

Remove the section of marked drywall with a zip tool or keyhole saw.

Remove foam from behind the portion of drywall with an EBX blade fitted to a high-power hot knife. Using a 6-inch sled will ensure that your cut goes in at a 90-degree angle. Taking out the foam allows the junction box to be flush with the drywall. Put the junction box in place.

Draw on the drywall the path between the newly installed junction box and the box where the power will be generated. Mark the path with the pencil. A path with straight lines makes pulling wires through easier, but be careful not to hit steel or plastic ties because the hot knife won’t cut through them.

Cut along the path you drew by using a circular saw. Set the saw's blade just long enough to penetrate the drywall.

Run the hot knife fitted with a conduit blade from the new junction box and along the cut you made with the circular saw. The blade should slide easily along the groove while forming a path for the wiring to travel behind the drywall. Make the cut about 1/8 inch wide.

Pull the wiring from the junction box through to the new junction box.

Fill the saw and hot knife cut with a standard joint compound.