Drywall and Dewalt cut-out tool?

[barneyz71]

I have a dewalt cut-out tool and am trying to cut out the A/C boxes with the A/C box cut-out tool that came with it.
It says to plunge into the box through the drywall then go to the right until you hit the edge of the box then pull it back out and plunge back in just on the other side of the box... then go around the outside of the box. The problem I have is I can not feel the box when I get to it. (there plastic) And I cut right through it until I realize that I went to far. Then When I find the edge and try to follow it I can not fee the edge and then I cut all over the place. Is there a different kind of bit for a plastic box?
Help!!!

[Rich]

Yes there is - it has a point on the end of it and the last 1/4" or so is smooth so it will not cut anything. I think Rotozip has the same size bits and I know they have one. I use a dremel with the rotozip bits and it works great too.

[barneyz71]

Thanks i'll check out Home Depot tonight and see if I can find one.