This is a box for popular AC-DC PSU size 86x58x33mm with switch 28x12mm
It's possible to find PSU in these size with 5/12/24 output (power will vary 20-36w)
High and low voltage sides are separated,
Two parts are screwed together with 4 3x16mm with flat head
Example on 24v 1a on aliexpress
Fireproof material is recommended, like Smartfil ABS F.P.