Tamper-resistant switch assemblies are provided including a first movement-sensing switch and a second tamper-sensing switch assembly, the latter including a switchable component and an actuating component. Preferably, the switch and switch assembly are housed within an encapsulated switch module, with the actuating component positioned above or to the side of the module. Mounting structure serves to support the module within a mounting opening and is operable to prevent removal of the switchable component and actuating component without significant relative shifting movement between the switchable component and actuating component. Any attempted tampering results in such relative shifting movement, thereby triggering an alarm.