I used this with a standard 3-wire round insulated extension cord (ground, hot, neutral in a black rubber jacket). This can look ugly on a smaller diameter cable (normal visible two-wire lamp cable) because the openings in the case are large. There were no instructions, but the switch was easy to figure out, especially if you already had a chord switch installed. . Simply strip away 1 inch of the insulation covering the wiring without cutting the internal wires. Insulate the ground and neutral…