1. A WIRING DEVICE COMPRISING A INSULATING SUPPORT HAVING AT LEAST TWO WALLS AT AN ANGLE TO EACH OTHER, A TERMINAL SECURED TO SAID SUPPORT ADJACENT THE INNER SURFACE OF ONE WALL OF SAID SUPPORT, A GENERALLY U-SHAPED SPRING ADAPTED TO BE SEPARATELY MOUNTED ON SAID SUPPORT AND HAVING ONE ARM THEREOF LOCATED IN ENGAGEMENT WITH THE INNER SURFACE OF THE OTHER WALL OF SAID SUPPORT AND WITH BOTH ARMS EXTENDING TOWARD SAID TERMINAL, THE OTHER ARM OF SAID SPRING BEING FORMED ADJACENT ITS OUTER END WITH A SHORT LATERAL OUTWARD EXTENSION WHICH TERMINATES IN A SHORT LATERAL PROJECTION, THE FREE END OF SAID ONE ARM AND SAID PROJECTION BEING LOCATED IN SUBSTANTIAL ALIGNMENT ADJACENT TO BUT SPACED FROM SAID TERMINALS AND WITH SAID PROJECTION LOCATED SUBSTANTIALLY PARALLEL TO SAID ONE ARM, AN OPENING IN SAID OTHER WALL OF SAID SUPPORT BETWEEN SAID ONE ARM OF SAID SPRING AND SID TERMINAL WHEREBY AN ELECTRICAL CONDUCTOR MAY BE INSERTED THEREBETWEEN IN ONE DIRECTION ALONG A SURFACE OF SAID TERMINAL, AND MEANS INTERGRAL WITH SAID TERMINAL EXTENDING OUTWARDLY THEREFROM IS ENGAGEMENT WITH THE OUTER SURFACE OF SAID PROJECTION TO FORCE SAID ARMS OF SAID SPRING TOWARD EACH OTHER AND TO PREVENT SAID SPRING FROM BEING LONGITUDINALLY DISPLACED WITH RELATION TO SAID TERMINAL WHEN SAID CONDUCTOR IS SO INSERTED.