Can you use a junction box to extend wiring?
Yes. You can definitely use a junction box to extend your wiring. To do this, start by turning off the power. Then inspect the place and cut the required openings.
How do you connect 4 wires to a junction box?
Connect the ground wire of the 3-wire cable to the ground wire of the 4-wire cable. Connect the black wire of the 3-wire circuit to either the red or the black wire of the 4-wire circuit. The red and black wires are the"hot" wires. Either wire can be used to power a circuit.