Please help identify switch! Thanks

[h2oman7]

Hello . This switch is located next to the solar control panel. Can anyone please tell me what it is for? New owner - Chinook 2005 Glacier. Thank you so much!

Sorry this image has turned sideways.

[Jlfchinook]

TV booster, maybe?

[djmoynahan]

This is the Water Heater 110 Power Switch, used for plugged into shore power or your generator. Never turn this on if there is not water in the hot water tank. When it's on, the light turns on.