Step 1: Turn off power to your light switch at your circuit breaker. Use a voltage tester if you want to be absolutely sure that the power to that switch is turned off. This tester can cost as little as $10 at your local hardware store.
Step 2: Next, remove the faceplate on your existing switch. Some have to be unscrewed, whereas others simply snap on and off.
Step 3: Now, unscrew the light switch itself and disconnect it from the wires inside the wall. Here it is important to note if the electrical box has a neutral wire. If not, you will not be able to install the WeMo switch in this location.
Step 4: Assuming you have the required wiring, connect the switch wires on the WeMo to the switch wires inside your wall. Simply line up the exposed wires and turn the wire connector clockwise to tighten. Tug on each wire to ensure that it's secure inside the connector. Repeat this step with the neutral wire. The ground wire is optional for this installation.
Step 5: Finally, screw the Belkin WeMo Light Switch into the wall and pop the plastic faceplate on over it. Your new light switch is now installed. Switch on the fuse and begin the app setup portion so that you can control your switch via smartphone or tablet.