A pigtail is a short wire about eight inches long. It is spliced with two or more wires in an electrical box with a wire nut. This allows multiple wires to connect to a single terminal through the pigtail which is connected to the terminal at its other end. It is very common to make use of a pigtail while doing electrical work. To make a pigtail, simply cut an eight inch wire and strip ¾ of an inch of insulation off each end. After that you're ready to terminate one end and splice the other.