After opening the pool this season, I wanted to provide some better protection for the power supplies for the pool accessories. This is a box I came up with to mount to the power post by the pool. In it I have placed the power supply boxes for the salt cell and the pool lighting. The lid is friction fit, and holds tight to the box.

Supports should only be needed for the lightning bolt on the lid, but you may be able to get away without them depending on your printer. Four walls and 5 layers top/bottom are the settings I used for strength, so infill was negligible.