A mechanical shunt for use in a socket of a string of lights resides in an otherwise typical lamp of a string of lights. The present shunt is a coiled spring shunt inserted in part into a hole formed in one of the electrical terminals in the socket so that it is cantilevered toward the opposing electrical terminal. The bulb holder carries a projection or a "tooth" on its bottom corner that is interposed between the first, cantilevered end of the spring terminal and the first electrical terminal when the holder is inserted into the socket. When the bulb and holder are removed, the spring shunt resiliently returns to engagement with the first electrical terminal.