I remixed the magnificent design from Marc Neuhaus to fit a Shelly 1PM.

However i was not happy with the DIN mount solution and changed it to a print-in-place spring loaded DIN adapter by Vorondesign (https://github.com/VoronDesign).

You will need:
 

• 1x Shelly 1PM
• 4x Wago 221, 3 cable version
• 2x M3 heat insert (long or short doesn't matter)
• 2x M3x10 cap head screws
• 4x wire terminator, isolated (please use them)
• 30cm flexible wire

Head over to https://www.printables.com/de/model/284123-shelly-din-mount-with-wago-221-terminals

The instructions there are very detailed.

Shelly will not be flush with the holder and poke out 2mm or so. There is also no sufficient protection against touch.

Printed in ABS, 15% infill, 3 perimeters, 3 bottom/top layers

Please note that you are probably dealing with mains voltage - take care.