Example of diy smart socket. This can be controlled by ESP8266 Home application. With this smart socket you can on/off any device in home.
A simple IR receiver setup controlling 2 LED by a relay board
A generic setup for museum exhibit automation. DFRobot 4 relay shield 2.1 and screw shields, Hitachi 16*2 Display shield on UNO or Mega.
Home Automation: control various home appliances with the help of voice recognition.
Usefull project when you wake up at night for washroom the PIR Sensor Senses your Motion and turns the tube light on.