A switch includes a body with a switch member on a top thereof, an extension extends from an underside of the switch member, and a substantially inverted L-shaped slot is defined through the extension. Two terminals extend through a bottom of the body, in which one of the terminals is fixed with a contact plate. The contact plate has a tongue with a free end, which contacts the other terminal when the circuit is ON, and is separated from the other terminal when the circuit is OFF. An operation member has a first end movably engaged with the slot and a second end connected with the contact plate. A positioning member having a first end pivotally connected to an inside of the body and a second end biasing the first end of the operation member. Under the current overload condition, the switch member is pivoted by a torsion spring to the OFF position.
