Im replacing plastic 1g2w switches for new plastic 1g2w's. It is a metal back box in a brick wall. One of the switch boxes in the living room doesnt have an earth at the box! It is wired in double sheathed singles so its not a case of it have being cut short. The switches are plastic and they have plastic caps that cover the plate screws. Is it acceptable to leave the way it is? Would it pass a Pereodic inspection??