The simplest I can think of is this: https://www.digikey.com/en/products/detail/sparkfun-electronics https://www.digikey.com/en/products/detail/sparkfun-electro

The simplest I can think of is this: https://www.digikey.com/en/products/detail/sparkfun-electronics https://www.digikey.com/en/products/detail/sparkfun-electron... use a step drill or other large-diameter bit to cut holes for cable glands, dremels to cut rectangular holes for power switches, and drill and tap holes for standard brass standoffs. IMHO everybody should have at least one cordless drill and drill bits, as well as an M3 tap. Then use Cable glands for wires going in/out, and nylon sheathing for the cables outside the box. If you take the time to make the holes nicely, the result often looks good enough that non-makers will think you are a god of manufacturing.