Corner Box

This is a highly customizable box/enclosure designed to fit in a wall/ceiling corner. In other words, a cube / cuboid that's cut diagonally. The sides are joined by opposed hook/groove pairs, the top by hooks.
The box works reasonably even if not printed perfectly. The current settings work perfectly on my printer.
The three edges may each have a different length, though for esthetics it's probably best to keep at least two of them the same. Edges can be chamfered to accommodate walls with not-quite-angular corners.
There are options for a cable hole (wall side) and up to four reasonably-aesthetically-placed openings for sensors (motion, light, temperature/air quality, camera, …) on the front.

The OpenSCAD text is documented and contains a heap of geometry stuff that is very instructive if you ever need to build things that fit together in non-right-angled configurations.