I don't do a lot of this, but when I do I just use a cordless circular saw and set the cutting depth so it's about 1/16 - 1/8 deeper than the thickness of the drywall.

Use a long level or straightedge to mark some lines and then make the cuts.  I don't have dust extraction attachment on my saw so it makes a big mess, but like NNF it's usually during a remodel so that doesn't matter.

You will hit some nails/screws but not usually a bid deal...

Setting up a track saw seems cumbersome and overkill for this type of work.

I use one of these. It's messy, but as long as your rest the guard on the drywall and make sure you angle it sharply so the blade will only cut the drywall It works OK.

https://www.cpomilwaukee.com/milwaukee-2420-20-m12-12v-cordless-lithium-ion-hackzall-reciprocating-saw--bare-tool-/miln2420-20,default,pd.html?ref=pla&zmam=31282435&zmas=47&zmac=731&zmap=miln2420-20&gclid=EAIaIQobChMIs67nz9WF3AIVhsDACh2mXwMaEAQYAyABEgJ97_D_BwE

[Link: kett-tool.com]

[Link: kett-tool.com]

[Link: bosch-professional.com]

Ran into this: [Link: makitatools.com]

And these: [Link: milwaukeetool.com] for a Sawzall

That guy must have been cutting across his arm- I have never seen a blade guard that closed so slowly that anything could get in.

Parallel edges are easy- the distance from the blade to the edge of the guide plate is known, so screwing a straightedge to the wall that's wide enough to create the desired opening and following it with the saw makes it very clean and professional-looking. The blade depth can be set so that it will never go past the backside of the drywall, so the wiring/pipe issue is moot.

Dust collection is another story- a fine-tooth carbide blade is needed but it can be better to reverse the blade so the dust won't be pulled out as aggressively. It will also do less damage to the paper on the surface if the gullets aren't very deep, especially if the saw uses batteries and the charge level is low.

I use a Milwaukee M12 Hackzall with a short wood blade as my go to drywall cutter.

Makes quick work of it, not as dusty as a spinning blade.

The only problem I have encountered is you have to be diligent with blowing the dust out of the tool when you are done. I have killed one by letting it get too plugged.

Richie,
as crazy as this sounds, it might be worthwhile to put a baggie over the blade end of the saw to keep drywall dust out. That's about the worst kind of dust, and I'll bet that the overheating due to a baggie cutting off air flow will be less harmful than drywall dust inside the saw.

We always chalk our lines and use a combination of oscillating tool and sawzalll with a fine tooth blade and can usually span about 2 feet a minute while cutting.

Ah, span. There's another word that I can add to my list.

When dealing with cabinetmakers and others who think they are speaking clearly about dimensions, keep in mind the three dimensions: height, length, width, depth, breadth, thickness, span, and gauge. Those are the three dimensions.

Other words come up which aren't strictly dimensions, such as tall and short, but those are not nouns. They can distract one from having a concise vocabulary for naming things!

That is what I do especially with plaster.

These tools:
1)Roto zip with vacuum attachment for dust collection
2)Shop Vac to attach to the dust collector
3)1"x6" board the length of the cut(cull lumber works great for this)
4)Drop cloths
5)Drill and sheetrock screws

Figure out your channel location on the wall and then screw the 1x6 from one end of the cut to the other. Use screws liberally. Bonus points for using a level on the board. Mark the upward orientation on the board.
Set the depth on your rotozip to just barely cut all the way through the rock and then add an extra 1/16" for those areas with a bit more mud. You want a single, clean cut from one pass. Attach the shop-vac to pull most of the dust out of the tool, and using the board as a guide, make one pass all the way around. This will give you a clean, straight line with about 8" of working space to drill through the framing underneath. Leave the vac running as you power off the rotozip, and vacuum out your entire cut line. Clean as much dust as possible at this point.
Now, remove the board WITH the sheetrock attached to the back of it. You may have to pull a screw or two through. This will keep the long, thin piece from breaking, or coming apart at the seams. Set the board and sheetrock aside. Remove any screws that protrude from the studs.
Drill the studs, run your wires. Using a pencil, mark the stud locations on the sheetrock above and below the cut(or the sides on a ceiling).
Re-install the sheetrock that you removed, using the marked stud locations. You should have room around the edge of the board to cleanly screw down the removed piece where the screws will be covered by tape. Remove the board from the sheetrock and tape/texture away.

Jason,
What an awesome method and thorough description! Usually we leave out details like "leave the vac running" but details like that often make a HUGE difference!
As I read it and mentally did it with you, I see maybe one detail to add: when you're screwing the board to the wall, remove any screws that you detect going into studs. That should be easy to feel.

Are you cutting the board out and saving it for replacement or discarding it?

Mario, the piece of drywall was carefully screwed to the piece of board so there would be a perfectly cut patch for the hole.

Yup, found it:

PHSJason said