I remember when GFI's first came out, they were so big that they wouldn't fit in a normal box. They came with a small extension box ( or ring) which you would have to place behind the new GFI recpt. and screw to the original box in the wall. Like a see through Wiremold box, except it was made out of plastic and it was the same color as the GFI. ( back then it was either Ivory or brown.)
