In this tutorial we will be making something I call a wifi controlled ac switch. (But iy also works for DC applications that are powered by a wall outlet) Basically we will make a small box that can control any ac electric current in your home, based on commands from your tablet or smartphone. On top of that it can be programmed to react to input from any kind of sensor. Tailored to your needs and limited only by your imagination.
Control an electrical appliance with your smartphone – WiFi – [Link]