There are a lot of available equipment using the phone line or having a GSM phone.


Note that the final solution may be a two-tier variant. First a base station that is connected to Internet, the phone line or have a GSM modem. This base station may then have relays locally (requiring you to use long mains cables to lamps etc) or use signalling wiring (serial or ethernet) or RF (low-end 433MHz, BluTooth, ZigBee, WLAN, ...), IR, ultrasound, or maybe use the mains wirings to forward the signals to one or more slave devices around your home, wheere each slave device then contains one or more relays or light dimmers.