Abstract: A progressive die sensor of the disclosure for sensing an unaligned workpiece condition includes a housing having an upper mounting surface engaged with an upper punch holder during mounting. A depression in the mounting surface is located in a spaced relationship to a downwardly extending probe that moves relative to the housing to indicate an unaligned workpiece condition. A switch received within the depression includes an actuating plunger that is moved by a push rod in response to the probe movement to cause switch actuation for generating an electrical signal which indicates the occurrence of the unaligned workpiece condition. A switch cover is received within the depression to cover the switch. The housing depression preferably opens upwardly and the switch cover includes downwardly extending side portions that receive the switch therebetween intermediate opposite sides of the switch depression.