The way we do boxes in brick walls is to either leave the box on a whip and let the mason install it, which I'm not too fond off.

Or more often than not, I end up going back after the fact with a masonry-wheel in an angle-grinder and cutting and chisling out a hole. Then I take take what I think is just a standard octagon box, 3.5 or 4 inches or whatever, and that's usually darn close to the size of a single course of brick and morter. Beat that thing in with a 3-pound sledge and it will never ever come back out.

As an aside, I wouldn't argue that brick can be a wet location, but I think it's awfully funny that it's perfectly code compliant to use a non-weatherproof box and a non-gasketed light fixture that goes on that box, and then worry about the fact that Romex coming into the back of the box might be in contact with morter. Maybe the whole system needs an overhaul. [Linked Image]

-John