This is the housing for a KeySwitch Interface by ATMakers.org.
The KeySwitch is a low-cost AT Switch Interface to allow a user to send keystrokes and mouse movements by activating external switches.
There are two tops - one has the ATMakers logo embossed on the underside, but that will only look good with translucent filament. For those with opaque filament, use the one with "opaque' in the title. That has very thin dots that will let the light shine through to show the activity.
A complete guide is in the works, but you can learn more here: http://atmakers.org/2018/10/circuitpython-creates-new-at-opportunities/
Also, here's a video of the assembly process.