I recently bought a 2007 Honda fit base and I noticed that there is a little blue light on the blank button next to the mirror controls. Does anybody know what it is or what it’s for?

 

That's an aftermarket install. It could be a number of things. Often I see them with security systems. You may want to pull the plastic down and check for extra boxes near the fuse box. I put a remote start box there myself.

 

Aftermarket alarm light. Not OEM for sure.