In-Wall 24-Hour Mechanical TimerCustom set this programmable timer to turn lights, exhaust and ceiling fans or heaters On and Off at certain times of the day the settings repeat every 24 hours, allowing you to set it and walk away. One potential use is to turn on lights in your house when no one is home, making it appear your home is occupied, deterring burglars and increasing security. Also, using this timer will save on energy costs when the wired appliance is only On when needed.