Here's an example of a 3 way switch. Basically you have to make sure the power is on. The current goes along 2 parallel lines. The switch doesn't cut the current but what it does is switch the black connector at the lower right to either of the red connectors. When the switch is in the top position the current goes from the black right to the red upper right. When its in the lower position the current flows from the black lower right to the red lower left. So, to check it out you have to make sure the Power is on, then just click the switch like you would with a real switch. You can see how the system works, without having to strip any wires.