How to thread conduit into an old-work metal box without cutting the drywall?

I'm looking to relocate a single pole switch (switch #1). There is an attic right above. There is another single pole switch (switch #2) on the opposite side of the wall right in the back of where I want to relocate switch #1 to. Switch #2 is controlling an outlet that happens to be at the end of the run on the same circuit. It looks like I can fish an extension of the switch line for switch #1 through existing conduit to a junction box in the attic right above switch #2. I'm debating how to run the wires down the finished drywall?

Option 1:
There is a metal EMT conduit running down from the junction box in the attic to switch box for switch #2. I can fish the wires down to the same switch box. Then, add a flexible metal conduit to thread the wires to the old-work box I'm going to install on the other side of the wall for switch #1. Question, how can I secure the flexible metal conduit to the existing switch box without cutting a hole on the wall?

Option 2:

Run another metal EMT conduit from the attic down for switch #1. Question: how can I connect the EMT to the old-work box? Can I use flexible conduit at the end of the run so I can secure it to the old-work box before pushing the box into the wall?

Any suggestion?

 

Switch 2 is an existing box already in the wall and fed by conduit. You want to add a second box directly behind it on the other side of the wall.

Blue is the existing box and conduit..... remove the switch in the blue box and see if there's a knockout that would allow connection to the red box and short piece of conduit.

 

I think bottom line it is sheetrock time, since you need to put box couplings on the box, and you need external access to do that, as well as flex cable connectors. Sheetrock can be patched, so if you try to minimize the damage at first, you'll wind up damaging more unexpectedly. I'd go ahead and cut a good chunk of sheetrock out, saving the piece, then make a repair after you have made all your connections.

Edit: misunderstood location of box. On opposite side of WALL, I was thinking ROOM. Yeah, what Pete said.

 

Thanks for the quick response guys...

PJmax,

Yes, Switch 2 is an existing box already in the wall and fed by conduit. I want to add a second box directly or within 6 inches behind it on the other side of the wall. Yes, there is an extra knockout in the switch box 2. My question is how can I secure the short flex conduit from inside the switch box 2? The fitting I have used before requires access to the outside of the box to tight the screws or nut to secure the conduit.

 

The stub is premade. All you'll do is tighten the locknuts.... inside the box.
You'll fasten the stub to the existing box so it doesn't fall in the wall.

 

Tighten the connectors and slide the box over the conduits.

 

A picture is worth a thousand words. I didn't realize I can secure the fitting in the flex conduit before fishing it to the existing box. Once the stub is in, I just need to tighten the lock nut. That make perfect sense. Thank you everyone... Wow, you guys are really quick!