You are looking for a keyhole saw. Any hardware or big box store will carry them. Once you see it you will figure out how to use it, no instructions come with it.

Yup, he's right. Stanley wallboard saw (yellow handle) will do just fine. The blade motion does the cut, so go easy on the pressure at first to keep it straight.

You are aware the width of that opening will only be 14 and 1/2" if the studs are on 16" centers, right?

"expansion recessed structured wiring enclosure"

Is that a fancy term for a circuit breaker panel? If so, be aware the only entrances/exits will be top and bottom---meaning you cannot set it close above the old unit or interfere with the wiring coming into the old unit.

You can cut a hole in drywall without any issues. When your desired hole is larger than the stud cavity behind that drywall, that's when you will start needing a professional to determine if that wall is loadbearing. You will need to install a header and jack studs to carry the load that the wall carries. Even if the wall isn't loadbearing, you'll need to install a header and jack studs. The header will be different sized based on the amount of weight it has to carry and the distance it has to span. To create that header will require you creating some temporary support for the ceiling joists that are supported by that wall. The amount of support too will vary based on the status of load bearing and how much etc.

In other words, for the size hole that you want to cut, call in a professional and just pay attention to what he does while staying out of his way.

Thanks all, I'll grab a new saw tomorrow.

Regarding the stud cavity, sorry for the confusion. I was just rounding up to show the difference in size between the opening I needed, and what I was finding online which were mostly for small outlet boxes. The enclosure is sized to fit perfectly between the studs. I have another one just like it directly below the location for the new one. We just finished building the house, so I know exactly what's in the wall behind it (photo documentation). We just didn't realize how much space we would need in the first enclosure while we were building, else we would have put the second one in at the same time.

I'll be using the top one for coiling the all of the cabling neatly, and perhaps enclosing the less frequently accessed RG6 splitters, freeing up space in the bottom for the network switches, router, etc.

It's not a circuit breaker panel, just low voltage connection point for the structured wiring in the house. There will be about 6 inches of clearance between the two, but the cables just feed from the top to bottom through each to the various mounted components like the cable modem.

Thanks again!

This post was edited by BlackAce on Fri, Jan 18, 13 at 21:30

Cut a small opening (2 inch by 3 inch first and then look in the stud cavity to check for plumbing and electrical.

Fixing a small hole is a lot easier than opening up and finding there is something in the way, especially if you could just move up, down, or top another stud bay.

A utility knife, metal ruler, and a hammer can be faster than trying to carefully saw an opening.

Score the drywall a couple times till you are most of the way through, then just knock a hole with the hammer and break the drywall back at the score lines.

For such a hole I would first use a straightedge and pencil and draw a line where you want to cut. Then, use a metal straight edge, like a framing square, and carefully cut in with a utility knife. Repeatedly cut, deeper and deeper and soon you will be through the drywall, with a clean hole and no danger of cutting wires underneath. I would not use a keyhole saw as it leaves a very rough edge and you could very easily cut into electric wires.

I always use a keyhole saw...I just make a hand size hole using shallow strokes so I don't hit anything running behind the sheetrock. Then I explore with my hand and proceed from there to make the correct size opening.