I know the problem with the sawsall is the blade grabs on the backing boards then the plaster comes loose all over. If used a sharp blade is a must. You can kill 1 normal blade per hole.
Screw driver chipping out works.
I had luck with a hole saw. Several cuts and then chipping out the corners for a box.
Those roto zip blades allways burn up on me. Maybe I have the wrong type.
I hered the idea of screwing a piece of pllywood all around the hole to be cut. This is to keep the lath from comming loose.
Tom
