This is a placeholder topic for “Rocker Switch - Round w/ Blue LED” comments.
These panel-mounting rocker switches have built-in indicator lights to let you know when your switch is engaged. They mount into a 20.2mm diameter hole and are rated up to 16A @ 12v. These simple SPST on-off switches have three terminals, the two that you would normally see plus a ground tab for the blue LED lamp inside. Although these are rated for 12v, the LED works with as little as 5V.