There is another type of switch even more common in industrial automation: inductive switch, where the trigger mechanism relies on inductive coupling between an

There is another type of switch even more common in industrial automation: inductive switch, where the trigger mechanism relies on inductive coupling between an external target and a coil in sensor (for all practical purposes the target is ferrous metal- they do usually work against aluminum alloys or stainless steel but at greatly reduced range). I usually see hall-based switches being used to detect pneumatic cylinder position- the plunger in cylinders has an embedded magnet and there is a rail on the outside of cylinder where you can fix a small sensor.