My lamp fell on the floor and smashed the turn peg on/off switch knob. Mine has a hole that held a spring, and the slot held a brass rod that when turned spring-snapped onto the lamp brass contacts to make the connection. Turning it rod the brass peg up the plastic ramp and rested on the non-contact portion. Turn once more and it snaps into the contacts.

I thought it was a goner but it works great. Hope it helps. I'd file the slot so the brass peg slides freely up and down with the spring.

Print on 100% infill. Hole at the top. Tree supports with a raft (because it's small). Cura prints this out as 54.34mm tall for me.