Haunted Television

The sun.

Your TV room's windows face west, and during certain times of the year, the sun's refracted rays come streaming in and strike your television's remote control sensor. Since the remote operates on infrared light, certain frequencies of light emitted by the sun are interpreted by the sensor as commands to turn on or off, or change the channel.

When you are home, you pull the shades, to keep out the glare of the setting sun.