My friend Zaffiro suggest to me this kind of solution for the lock in a mechanical push button and so ... i did it.
It's really easy to print but print all the parts at 100 microns (0.10 mm) for best result.
It's easy to print too. Follow the shot and u need only glue in a part.
This work if your wall is about 3 mm wickness and it works in ALL my mechanics box mod with 12 mm push button hole.
Good luck !