Enclosure for a larger limit switch, specifically this one: "Cylewet V-154-1C25 Micro Limit Switch" from Amazon. The flat piece bolts on top of the other piece, sandwiching the limit switch. For clarity, the photo does not show the flat piece - it would go on top. The holes are 8mm and 16mm apart - to match with Tetrix and Matrix structural elements. Bolts (6/32) should be put through two of the holes. The flat plate is designed to be customized - edit the "switch_cover" module in limit-switch-large.scad to create your own customized plate - that can potentially extend beyond the footprint of the limit switch so that it attaches in the correct position.
Together, the housing and plate provide a level of protection for the switch lever. Overall, this is pretty robust, but a bit bulky.
Taulman TECH-G PETG