This build requires some electronics knowledge, soldering skills, and an ability to manhandle electronic components without breaking anything.
Working with lead solder is not good for your health because of the fumes, so I turned an old PC case fan into an adjustable fan for my soldering area.
92x92x25 mm PC case fan (mine was a Sunon EE92251S2-D130-C99)
Power Switch (I used an NTE 54-517)
Female-to-Female jumper wires (optional)
USB power source
I screwed up the initial measurements and didn't realize until everything had printed. I opted not to fix it because it would have made the design bulkier. The workaround is to bend the prongs of the power switch far enough to be out of the way but with enough space that the metal is not touching the plastic or the prongs are not touching each other.
Assuming that anyone who is working on this design has skills in soldering and electronics, so the build should be easy to figure out. If not, let me know.