Low Profile Masonry Receptacle box?

Lovegasoline

Low Profile Masonry Duplex or Quad box?


I have an old building with an interior masonry wall of some sort. I’m running BX cable along it for a few feet where it terminates into a receptacle box.

The wall is covered with plaster. I am cutting the plaster away and making a groove in the masonry for the BX, then I need to chop out a space for the box and the cable clamp. Not easy work. I want to make it as easy as possible.

Do they make special masonry receptacle boxes for this sort of application? In particular, is there a special low profile receptacle box?

Also any tips for grooving out the masonry? Cold chisel and hammer is slow going. Maybe successive shallow drill holes (dotted line) with a wide masory bit, then clean out the other sections with a chisel?

Thanks for any tips!