The process requires safely disconnecting the wire at its source, either at the circuit breaker terminal in the panel or from the last working junction box on the circuit. The safest first step involves using a non-contact voltage tester (NCVT), which detects the electromagnetic field created by alternating current without physical contact. For a more precise. Before beginning any work on an electrical box, de-energize the circuit to mitigate the risk of shock or injury. My primary question is: #1 How to terminate unused wire at a junction box? I was able to completely fish out the wiring for the lights and removed it entirely from the junction box, but the outlet wiring is not. al disconnects safety. However, if not handled properly, they can pos serious safety risks.