installing a masonry box in brick for exterior outlets & light fixtures

[Jrland]

I've been searching how to cut in a new masonry box for an exterior outlet and fixture. What I've seen shows to cut the opening oversized for a masonry box and mortar in place. My question is should the box also be screwed to the wall framing before the mortar is installed around the box? Thanks

 

[Stuff]

Sometimes screwing in can make it more difficult to adjust and center.