The source for this circuit is at an already existing light fixture and a 3 wire switch loop run from there to the switch box.
How to add lighting to an existing wall switch.
To add an outlet to a light switch you start by making a pigtail using the hot wire the wire going to the fixture controlled by the switch and a third length of wire.
Wiring diagram for a new switch and light.
Examples include adding lighting underneath kitchen wall cabinets where the existing switch will be at the exact height of the new lighting or installing an outside light by routing the cable directly through the back of an existing switch box to the outside.
Electrical switches typically have 110 volt power connected directly from the circuit panel.
After you ve determined that the existing switch box will work to power the new light it s time to shop for the sconce and pick up the remodeling box cable and electrical connectors you ll need.
In this diagram a new switch and light are added to an already existing light switch.
The biggest challenge is planning the cable route and running it from the fixture to the new wall switch position.
Choose the fixture first.
Hook up the outlet as you normally would.
This 3 wire switch loop satisfies the nec requirement of a neutral in the switch box.
You then splice all the white wires and all the ground wires in the switch box together.
Adding a wall switch to a ceiling fixture can be done in a matter of hours.
Finally complete a simple calculation to see if the existing switch box is large enough to accept more wires.
How to tap into an existing wall switch.
If the wall is heavily insulated push conduit through the insulation and then feed wires or cable through the conduit.
The switch will pass the electricity from the panel to a light.