Round Box in Exterior Brick Wall

[Ponchik]

i always use a 3.5" carbide holesaw and cuts a nice clean hole.
http://www.mkmorse.com/products/index.aspx?product=18

 

[220/221]

Surface mount a pan box if the canopy will allow it.

I just didn't think the holes in a device/switch box would
match the holes in the mounting hardware for the light

Generaly, the hardware will line up. If not, use your tools and unleash your inner engineer.

 

[Hv&Lv]

I have a couple of these:http://www.toolfetch.com/dry-concrete-core-bits.shtml
You can find them at several different places. You really have to be careful and slow in cured concrete or the teeth will be gone in no time.
For green concrete or block, it will cut like butter. Brick is a little slower cutting. I use these for drilling nice looking holes for conduit, also for gas log, range, and dryer vents. the nice thing here is no chipout on the other side like a percussion bit. Nothing worse than having a crappy looking hole on a nice brick wall, and trying to explain why the brick or mortar is cracked or missing past the light cover. HVAC people seem to be the worst about beating a hole through a brick wall, then making a 10X10 cover plate for a 4.5" hole, or using a tube or two of caulking...