How do you wire a switch outlet combo circuit to an existing 3 way light switch?

Answer:
In a three-way switch arrangement, one switch should have its black terminal (screw) connected to the line source, and the others black terminal to the load.
If the circuit neutral is present in the box housing the line connected switch (somewhat rare), then you can simply tap the line conductor from the switch and attach line, neutral and ground to the current tap.
If there is no neutral present, then rewiring would be required.
First answer by Mcx8xu. Last edit by Mcx8xu. Contributor trust: 3 Question popularity: 1 [recommend question].