The Best Add Second Light To Existing Fixture Ideas. Web you can't use the wiring of the existing light. Connect a 2.5mm 2 spur cable to either a socket outlet or a junction box by.

Adding a new light fixture to an. Match the black and white wires on the cable to the ones on the electrical box, and attach a wire cap to each connection. The switch is at the top of the stairs and there is another switch (switch 2) on the circuit at the basement door.