This is an enclosure for the Sonoff 10A Wifi controlled switch. This Sonoff module is very popular because of its attractive price. But it only allows to splice it into 2-wire cables that don't have ground.
If you want to control an outlet that does need a ground wire then that wire has to be outside of the Sonoff module which makes the entire solution less esthetical and most likely also unsafe.
This enclosure fits the Sonoff module together with all the wiring and adds additional cable strain reliefs for improved safety. The strain relief only needs a small zip tie, no screws required.
This enclosure also keeps the option of manual control by adding a simple push button. The button only has to be placed in the proper location in the case before closing the case and allows to operate the push button of the Sonoff module inside.
Furthermore, the Sonoff module features a green control LED to indicate its switch status. The enclosure has an area with a thin wall for this LED to shine through. If you should use some non-translucent filament then you can go into the scad file and uncomment the corresponding line to get an actual hole for the LED.
This can be printed with either ABS or PLA. I used a 0.4mm nozzle with 0.3mm layer height and 25% infill. No support needed.