In general, to pigtail, a ground connection, first switch off the power supply to the electrical box you are handling. Next, wind the ground wire or wires together using pliers. Make sure the wires are. Whether you are a DIY or professional electrician, you will almost certainly use pigtail wires at some point in your project. Below I will provide straightforward. A pigtail is a simple wiring technique used when installing electrical outlets, switches, or other devices inside a junction box. Cut 6 inch lengths of THHN or unsheathed Romex wire.