I took apart a faulty computer mouse and salvaged the micro-switches (12.6 x 6.5 x 5.7 mm) and LEDs, wires etc. and I wanted to reuse the micro-switches for proper endstop usage: small encasing with a lever to function as endstop.

Note:

• first tests show bad repeatability, means, it's not suitable for Z axis endstop where repeatability is crucial; Update: after 10-20 homing, the switch started to trigger nearly the same distance.
• if you have power-loss/resume-print feature, these aren't suitable as X and Y position might change slightly (~1mm) at each homing (see above)
• I have no long-term usage experience yet using this endstop.