Just a simple waterproof in-line power switch for power cords etc. (including USB cables), e.g. for outdoor lamps or anything else you can think of...

Of course, strictly speaking, very few things you print will be "waterproof", so splash-proof might be the better definition (think of it like those watches, where it says 3 ATM water resistant but when you read the small print it says "don't use for swimming, in the shower...."). You can further improve its water resistance by painting the inside with epoxy, sealing all electric parts and adding silicone to all seams.

What you need for this project:

• One of these little rocker switches: (21x15 mm) rocker switches (approx. $ 0.15)
• Two ordinary M3 screws (10-16 mm) with countersunk head
• You will need flexible filament for the switch cover and cable inserts: TPU 1.75 mm Flexible Filament
• Optional: I use some cheap epoxy resin to make my prints 100% waterproof whenever needed: Epoxy Resin (approx. US $5).

Printing and Assembly: Printing should be very straightforward. NO SUPPORTS or adhesion needed. Print one each of PartA and PartB in your favorite material and color (PLA, ABS, PETG...). You will need some kind of flexible filament (see above) for the switch cover (one copy) and the cable inserts (2 copies). Black looks good but you won't see the switch, so white/transparent is ideal. Slide the cable through the two cable inserts, connect your cable to the switch, slide the switch + the cover from the side into the respective opening of Part A, close with Part B, add the two screws.

HOPE YOU LIKE IT AND IF YOU LIKE IT PLEASE LIKE IT! Enjoy!

Remember: whenever dealing with high voltage, make sure that you absolutely (!) know what you are doing and to be extra careful. Better SAFE THAN SORRY! No warranty whatsoever.