Simple case that houses a multimeter (display) and a power switch, the case can be screwed to a surface.
CAD files included, feel free to reuse.
Components used:
Multimeter https://www.amazon.de/gp/product/B08NTMX62K
Powerswitch: https://de.aliexpress.com/item/32424649963.html
The author hasn't provided the model origin yet.