New to this forum. Sorry if this is already discussed. I just bought a new shaver socket which does not fit the existing back box. The issue is not with the depth but with the distance between the fixing centres. The new socket is 120 mm between centres whilst the back box is less though it looks like a double box. Did they used to make non standard back boxes? My on is about 120 x 80. Where can I get a shaver socket to fit this box? In help appreciated.