This design can be used to cover a Solid State Relay (SSR) like this from Aliexpress:

https://www.aliexpress.com/item/1005005622403328.html?spm=a2g0o.order_list.order_list_main.34.1ca018023mtcXT

My usages is a USB powered mains switch. I'm using it to power extra devices (table light, audio amplifier, extra monitor etc.) on/off depending on if my main PC monitor is on or off.

Instruction:

This design requires knowledge to electricity and required safety precautions! Please only make this device, if you're skilled to work with mains supply!

There is a window in the lid, making it possible to monitor the SSR Led. The Lid is secured with two m3 screws from the bottom side of the box. (the lid has to be mounted before the box is mounted to where is shall be installed.

Printer settings:

Nozzle size: 0.4-0.8mm
Layer height: 0.2-0.6mm
infill: 10-20%
Support: Not required if objects are oriented on the flat surface.

Material: Your choice!

Required parts to print:

SSR-Box: 1 PC

SSR-Lid: 1 PC

Power cable relief: 2 PC

USB Cable relief: 1 PC

For assembly of the box requires:

M3 heat-inserts: 8 PC 

M3 screws, 8-12 mm long

M3 countersunk screvs, 10-12 mm long