I purchased '25mm Roller Lever V3 Microswitch SPDT 16A 250VAC' microswitch for my loft door to have the lights switched on and off when the loft door is closed and opened.

I then made a box that allows holding of the microswitch, cable entry and screw holes to mount on a surface of choice. There is a lid that is a tight fit and aids in holding the switch in place.