Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4833227.
This is a base for the end of the BTF-200-12 (12V, 16.5A) version of this power supply: https://www.aliexpress.com/item/32670477391.html
It covers the end with the terminals to hold the supply upright (like a Wii). There are internal holes for routing wires to the terminals. The 110V/220V AC input goes in one side and the 12V DC comes out the other. There are 2 screw holes and 2 holes that I think are for venting because they aren't threaded. The screws are optional since it's a pretty snug fit.
In the future I'd like to add some sort of mount for a switch/plug, but this works good enough for now.
This is the switch I used: https://smile.amazon.com/dp/B07RRY5MYZ
Tinkercad: https://www.tinkercad.com/things/2xEo0w57a2n-btf-200-12-power-supply-base-v2a