I bought a bunch of empty PCBs, which I for example use to build a fan controller for a fume extractor to use while soldering or printing.

Since most of these PCBs will eventually need some sort of enclosure I created this parametric model that allows me to create a box for any size PCB.

The lid snaps in tightly, removing the lid might require a small screwdriver or spudger.

A couple common sizes I added 3mf files for, but if you need a different size, the Fusion 360 file is available as well. 

If all you want is to run a wire to the PCB, you could create some holes using negative volumes in your slicer, or simply drill some holes in it after you printed it.

Customization

For customization you probably only need to touch the boardWidth and boardHeight parameters. I've added comments to all the parameters in the Fusion 360 file to clarify their purpose.