I wanted a small mount for a single rocker switch that I could mount to 4040 extrusion at the base of my Ender 3 printer next to the LCD panel. This is the switch that I used: https://www.amazon.com/gp/product/B0725Z6FR7/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

Any switch with the mounting dimensions of 11.5 mm x 18 mm will work as there are several variants of this particular switch. This mount will also work on other extrusions such as 2040 and 2020 since the mount is in line. I used 3 mm x 8mm button head screws and 3mm hammer nuts to mount this to the extrusion.

There are two outlets from the sealed box to accommodate wires to go out the back of the mount or out the side of the mount.