Wood panel over sheetrock - recessed electrical boxes

I have a room where the previous owner had turned into a "library". Built in bookshelves, wood paneling all over. I removed one of the switch covers and noticed the panelling was installed over the sheetrock, and therefore the electrical box sits far back from the finished wall. I assume it's the same for all the boxes in this room. Box is metal with conduits. They cut the rectangular hole smaller than I expected, so that the device mounting holes on the mud ring are covered up. Image: http://i173.photobucket.com/albums/w67/143house/11th/IMAG1756_zps8f6c079f.jpg So they used tapered wood screws to mount the switches on the thin wood panels instead.