An auxiliary switch sub-assembly is provided for a telecommunication system circuit breaker including a housing having an opening, separable contacts inside the housing, and an operating mechanism operating the separable contacts between open and closed positions. The operating mechanism comprises an operating handle operable among a first position corresponding to the separable contacts being open and a second position corresponding to the separable contacts being closed. The operating handle has a first end protruding from the opening of the housing, and a second end. The auxiliary switch sub-assembly includes an auxiliary switch including an actuator, and a mount attaching the auxiliary switch to the operating mechanism of the circuit breaker within the housing thereof. The actuator is mechanically actuated by a portion of the second end of the operating handle. An electrical switching apparatus employing an auxiliary switch sub-assembly is also disclosed.