With many using USB keychain lights on Prusa minis for primary lighting, I thought they could be used to observe first layer print without mounting them to the printer.  This was made as a standalone light frame that fits under my printers sidedrawers.  It uses a USB keychain light and a USB cord with a built in on/off switch.  It is a tight fit for the USB cable head. I also took the keychain plastic shield apart to put it in the frame/USB (back shield, then light chip, and then front shield). Height is also set for noise reduction feet on my printers base.

PETG with support for cable opening only at the bottom.