I bought a tray of 50 of these tiny microswitches from Goldmine-elec.com for a very reasonable price of ten dollars U.S. As can be seen, both the switch and a transistor easily fit on a dime with room to spare. These will enable me to make some auto shutoff Joule Thief lights that are much smaller than previous ones for a very reasonable price.
These tiny critters are really micro sized. The trick will be how to mount them so they don’t get damaged yet are still easy to actuate.
Typical prices for a momentary contact pushbutton switch are more than a dollar, and they are much larger in size.