It's a power switch for the (optional) Winegard WiFi antenna booster upgrade. Just look for the blank electrical plate on your ceiling, underneath where the Winegard antenna dome is installed on top of your roof. Remove the plate and you'll find the power wires. (I'm assuming you didn't get the optional Wineguard system; I didn't either). Feel free to use the power wires and the switch for whatever you wish, such as a cellphone booster, WiFi booster, amplified TV antenna, or similar DIY installation, etc.