Detecting vehicle movement using a washing machine pressure switch. The switch would be triggered by air pressure when the vehicle crosses a hose. Just remember to plug the end of the hose that's not connected to the switch! So there are four applications but there are lots more. It's certainly worth salvaging these very sensitive switches!
These switches also look a lot like washing machine pressure switches, except they have multiple electrical terminals (six or even nine) and don't have external level adjustment. However, some have screwdriver adjustment for both the trip levels and the hysteresis. When extracting the pressure switch from a washing machine, be careful that you don't also inadvertently