A WiFi router based appliance control system and method. The router infers the presence of certain human or animal users based on the association between the user and the WiFi signals emitted by WiFi equipped computerized devices typically associated with the users. The router is configured to control various appliances (router controlled devices), and based on the inference that certain users are or are not local to the router, and various algorithms programmed into the router, the router will in turn control the various router controlled devices. Thus for example, if the router detects a WiFi equipped smartphone coming in range, it can respond by automatically turning on lights or adjusting heating and air conditioning appropriately.