Can't Fit 2 Switches in Double Gang Box

I just finished wiring two of the newer Red Series (VZW-31-SN) switches in a double gang box, and when I tried to install the switches into the box, they would not fit together. The right side of one is overlapping the left side of the other by a couple of millimeters so they will not install side-by-side.

This seems strange to me because a) this series doesn’t have the heat sync tabs, so there should be nothing to remove and b) this is new constructions so the gang box should be pretty standard size.

Any help or advice appreciated!

I assume you’ve already made sure each is using up its max wiggle-room available in the (Reds’s) pill-shaped screw slot holes?


I’m definitely not using all of the pill-shape space, but its because the corners of the switches are already pushing against the respective edges of the box, so there’s no room for them to move any further. It appears as if the box is too small, or the switches are too wide…

Ah, yep, that’d do it then… Odd that a fairly modern 2-gang box is that skinny… I don’t have any Reds but I assume they’re the same size as Blues, and I wouldn’t consider that a particularly fat/wide switch at all.

It’s not the easiest thing to do in the world, but it’s (typically!) not as hard as it sounds either (especially if drywall) – you could replace the box with a slightly wider one. Just takes a bit of time and patience and a saw capable of widening the wall’s box hole.

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Can you post a picture? Where are you located?


You have a metal mud ring? I had to use a chain saw blade sharpening file to file mine down. Was super easy and quick!

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Did you break off those metal tabs on the sides of the switches? I believe theyre meant for dissapating heat, but they are removable. I had to do that to many of my switches.

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I don’t think the new 2-1 Reds have those.

Here’s where mine got stuck on the mud ring. It was easy to file a bit of the metal mud ring off.


Thanks for all of your responses to date. I’m attaching a few representative photos.
I tried hitting the corners of the box with both a file and a Dremel aluminum oxide grinding wheel. A fair amount of effort and they’re still not quite fitting properly.

FWIW, I just measured the box and it’s only 3 5/8"w whereas it seems that most 2-gangs are around 4"w (not sure why I didn’t check this earlier)

yeah the new reds don’t have the metal tabs.

Unfortunately, that box is going to be a problem. I’m guessing it’s pretty old from when switches took up very little room in the box. Most modern new work metal boxes are squared off, not rounded as yours as.

I think the solution is going to be to cut that box out and replace it with an old work box that has tabs that can grab the sheetrock to hold it into place. If your local code allows a plastic box, I would use that over metal. If you’re using conduit, then swapping out is off the table.

It’s hard to tell from the pics, but some boxes use a mud ring, which attaches to the front of the box. I do see a paint line toward the front of the box, possibly indicating that the box was installed, then the wall sprayed, then the ring installed, so you may have one. If you do have a mud ring, you might be able to remove it and substitute for one that is more square.


I’m also wondering if you can just grind about 1/16th of the side of each switch’s backstrap. Doesn’t look like you need much.

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I would imagine that the box is mounted to a stud on either the left or right side… just ask a buddy to borrow their oscillating tool with a metal blade and just cut the screws off and put in a newer bigger box. I think thatll be ur only solution tbh. Or maybe file down a bit of the switches so they dont rub? Would they fit side by side if you just filed down like 1/8 of the metal in the middle between the switches… im not saying the body of the switch… the front metal of the switch.

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You are going to want to evaluate whether or not you have conduit in order to assess the ease in which the box can be swapped, so you can look at alternatives if that is too tough. Take a look in the opening above the box and at the fittings at the top of the box.

Are the green ground conductors stranded? If so, there is a greater chance that you have conduit.

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Edit: This was not specific to this situation, but more for others who might come later, especially if you don’t realize you have conduit and you think replacing the box is gonna be easy. Thanks to Bry for pointing out what I said could be confusing as clearly AndrewG has ground wires!

Or if there is no ground at all, then hope you have conduit. I’m in the Chicagoland area and all our residential is in metal conduit so we don’t have any dedicated ground wires.

Did you look at the pictures the OP posted? The green conductors are the grounds, which is why I asked if they were stranded.

Or sorry I was just talking in general, should have made that clear.

I can probably trim down enough of the ‘overhang’ metal on the left side of one switch and right side of the other to make it fit. It would only be a mm or 2 on each, but do you think that would affect the minimum required heat sync surface area?

I dont think so tbh… i have maybe 13 reds in my house and i dont feel any warmth at all from them… i got the old ones too and cut off so many of the ends for them to fit in my boxes… no issues… if anything, maybe wrap ur switches in electrical tape atleast once to ensure the screws for the terminals on the switches dont touch the metal box or the other switch. Just a little step to prevent a short since the space is so tight.

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