Electrical Box Question

[DrQ]

Hello, does anyone know what this switch does? It it light up and slides up and down turning it on and off.

Any suggestions?

 

[Swfla]

The red lit switch is something that was added to the boat by a previous owner. Not standard equipment. So only a guess. Maybe a light switch for the a light in the vicinity? But it could be for a hundred different things. If it is a light fixture and the bulb is burned out, it'll take a while for you to look around and maybe find it.
Hint for new members: your personal profile should have as much info as possible as the make, model, year, size all can help us answer your questions. A photo of the boat is a nice touch as well.

 

[wkearney99]

When you turn off breakers, what causes that light to go out? That'd be your simplest place to start. That is unless there's something that makes noises when the light is illuminated, like an engine compartment blower or something.