In my 1970 house there are many metal 4x4 electrical boxes that are shallower than the standard 1-1/2" depth. They measure about 1/8" over 1" with only 1/2" knock out holes.

They fit perfectly on top of the masonry wall, with a 3/4" furring plus 1/2" sheet rock, resulting in the box being flushed with the finished wall after adding a flat mud ring.

I have to relocate a few things and need to add two more of these boxes, but I couldn't find one, went to two local supply houses and they don't have anything either.

If I don't find them guess I have to chip some concrete.

 

While we are on this subject, can someone tell me what this part is for?

RACO 976 Box Extender Ring 1/4-1"



Is it the same as an "extension ring" except this one is adjustable? I have been looking for an extension ring less than the standard 1-1/2" but never knew one existed.

Will this work on a 4x4 two gang box?

 

That extension you show slips inside a recetangular device box. The 6-32 screws go through the holes. I think they are a short circuit waiting to happen. I like the Arlington BE1 and BE2 much better.

I have only seen those extensions in a single gang device box.

 

If I understand correctly you are saying they do not "hug" tightly the inside of a box but is attached to an existing mud ring?

 

Yeah I think you'll have to do some chipping. I know there are 1-1/4" deep 4 square boxes (example), but none that I know of less than that.

 

Those split extenders basically float on the device screws and the steel is springy so they could easily short out the wiring screws on the side of a switch or receptacle.

 

I agree with pcboss, and you will too, once you see the Arlington rings. They are plastic and you just cut them down with a drywall knife or a scissors. The BE1 is 1-gang and the BE2 is 2-gang. They also make one for round boxes.

 

Thank you for the great info. I will check out the BE1 & BE2.