Adam Jochna posted a printed micro switch. I thought is was quite clever to utilize an inexpensive 1/4 inch tactile switch. Here's his posting: https://www.thingiverse.com/thing:756126

I designed a similar part, but it includes several enhancements. First, I didn't like having exposed terminals. So, I made side covers that have slots for wires to escape out the bottom.

Second, the 2-piece body/lever was difficult to make work correctly. Too much trimming had to be done to get a nice, smooth action, without making it too wobbly. So, I integrated a hinged lever to the body. The movement is clean and the lever has no side play.