light switches

Hi guys, I’ve been trying to figure out what the switch in the bathroom does on my 04’ 330 express. It’s next to the outlet behind the toilet on the wall. See attached picture. Anyone know what this switch does? Thanks!

My spreader switch in the dome light stopped working on my 2004 sailfish 282. It seems relatively simple to rewire this to one of the unused rocker panel switches through the hard top tube. Is this a good idea? Why weren't they wired this way originally as opposed to the dome light? Are there...