A solid state switching circuit for energizing a lamp (L) is connected around a fuse (12) across an AC supply for detecting a voltage differential at the opposite sides of a blown fuse and applying that differential across the control (g) and switching (c) electrodes of the solid state switch (SCR) to render the same conductive. Current limiting resistors (RL1 and RL2) are placed in the ends of wire conductors which are to be connected at opposite sides of the fuse, thereby to limit current flowing in the conductors over the entire length of the conductor, minimizing electrical shock hazard upon damage to the conductor.