Mount vanity light fixture box overlapping stud with more wiring volume than pancake box

electricallight-fixture

I'm replacing an off-center vanity light fixture in a bathroom. I removed the old fixture and discovered that a stud partially overlaps the location where I need to put the new (centered) fixture. One possible solution is to attach a wood block to the side of the stud and attach a pancake box.

However, the old off-center box did not only contain wiring of the circuit to the fixture– instead there were two Romex lines entering the box– a 12/2 and a 12/3. There were 3-way connections between the corresponding wires of the 12/2, 12/3, and fixture, with the exception that the black fixture wire was wired to the red 12/3 wire for a switch.

In any case, I think this is too many wires for a standard 6 cubic inch pancake box. Really what I need is something like a partial pancake box with a little room out back on one of the sides, but I don't think they make this.

What's the best way to mount a light fixture box overlapping a stud while getting greater than 6 cubic inches of room?

Target mounting location (before removal of old box)

Best Answer

A saddle box is what you are describing.

Since you want to be slightly off center of the stud but still overlapping it, you should get a one-sided saddle box and shim the stud on the left so the box can be mounted securely. One sided boxes are harder to find, but they exist. They aren't called saddle boxes because without the two sides they don't resemble saddles. They are sometimes called fan boxes, but if you search for fan box you'll get all kinds of other things. Here's one just so you know they really exist.