My switch does not lock into the panel as it should. Removing the faceplate nut, there is a notch in the panel and a notch in the switch but nothing that goes into the slots to keep it from rotating. I've looked at the parts illustration and at numerous pics of new switches but nothing shows the detail of what goes into the notch. It does not appear that a "key" was sheared off from the switch body. Anyone know what I'm missing? I'd buy a new switch if I knew that it has the key to align with the notch in the panel. Thanks