This is a more reliable enclosure for the SOnOff IoT device allows mounting it on a power cord.
In my case I am using it to control my 3D Printer remotely.
Screws are M3 x 10mm
Print with 100% infill 0.4 or 0.5 nozzle.
Mains power is dangerous and it is not a joke. Know what you are doing, print this and use it at your own responsibility.