Summary

This is a 2 part button housing for an arcade momentary switch.

Amazon Link - https://www.amazon.com/gp/product/B01MRWL6DW/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

The button snaps in the top hole and the wire comes out the side. I use these for momentary switching on/off Sonoff Basics

There is a hole on the bottom which can be used for mounting.

The two parts can be screwed together with a standard #4 machine bolt.