A light unit includes a bulb having a light source with lead wires and a separator, a switch member that includes a support member and a pair of spring terminals, and a socket having two or more conductive terminals and adapted to receive the bulb and the switch member. The switch member is adapted to cause the pair of spring terminals to contact one another to form an electrical short circuit across the pair of conductive terminals and the light source when the bulb is completely or partially removed from the socket. The lead wires form an electrical connection across the conductive terminals and the separator breaks contact between the pair of spring terminals when the bulb is seated in the socket.