I bought 8 pieces and they all work perfectly. Please do not pay an electrician to install. That's a waste of money. I have no electrical knowledge and they were VERY EASY to install. Here are the simple steps: 1) Turn off the main switch. 2) Disconnect the old circuit. 3) Screw the live black wires to the area marked "black". 4) Screw the white wires to the area marked "black". whiteβ and 5) Screw the bare metal wire to the ground area (green). That's all. Many people (especially Caucasians) are overly afraid of installing electrical equipment. Once again, SUPER EASY to install in any home. *This ONLY works on single sockets!