Thought this was going to be an easy project but it's not starting to be that way. What I want to do is install a ceiling fan in my bedroom which does not currently have any type of ceiling fixture whatsoever. I do have a switch that was used to control switched outlets. I removed that switch box (single gang) with hopes of installing a 2 gang old work box in its place. The single gang box was nailed to the stud so I used a sawz-all to cut the nails from the stud. That is when I discovered the 2 gang box was smaller than the single gang box's hole. It is not as tall as the single gang box therefore the "ears" will have nothing to catch on when I go to secure it to the wall.

I would have used a combo switch (light and fan control switch) but the single gang box already had four sets of conductors in it so that is why I decided to use a 2 gang since I would have had to install one more cable into the box.

Do they make taller 2 gang old work boxes? If not, what are my options? I thought about filling the hole and moving the 2 gang over a bit but realized the wires may not reach to the new spot.

Thanks in advance.

There are ceiling fan boxes already mounted to a bar which gets nailed to your ceiling joists. I realize this doesn't answer your question, but it provides both a mount and the ability to move the box anywhere on the bar. If this works for you, you should be able to find them at any home improvement center. The ones I've seen have an octagon box as part of the arrangement. And as far as extending the wires... you can do that with a junction box. But you cannot use a junction box unless you can access it. (can't bury it in ceiling or wall)

Would the B255R-UPC here: Carlon Image Gallery
Work for you?

There is an approved way too splice within a wall and not requiring a junction box. It's a special connector by AMP.
Since your doing so much work, you might as well make sure you have a neutral available for some devices.

There is a box available from Lowe's for ceiling fans that installs through a hole. You crank the gripper so it extends to the sides of the studs.

If you can't find what you need don't just patch and move over. Enlarge the hole and nail in a new box, then patch the wall. You'd be fixing your wall anyway and this would save you the hassle of wiring that comes up short because a box got moved.

I'd already decided on how I would install the ceiling fan box and thought it would be the appropriate way. I was going to find the center of the ceiling (make sure a rafter wasn't in the way) and cut the hole. Go to the attic and attach a ceiling fan box to a 2x4 (match it with the hole) and install between the rafters.

KISS... I think that box may work if it indeed is bigger. I'll have to run to my home improvement stores tomorrow to see if any are available. Also, what did you mean by having a neutral ready for devices? They are all going to be connected together.

Tev... thats an idea but I don't want to go that route if I don't have to. I'll see if I can find a bigger box. If not, I might give that a shot.

Here is an example of a fan control. http://www.smarthome.com/manuals/45059.pdf

Note that a neutral is required in the box. 2 power and 2 to the fan. A lighting control can be wired the same. You have one power in cable and a cable to the light and a cable to the fan.

It's wired now with power to the switch rather than power to the ceiling box with a switch loop.

Probaby too late, I would consider using a 1900(4"x4" Box), likely an X ring with a 2 gang mudring. Should be able to do all work with in the 4" X 4" hole, wall plate will cover the rest, can be done with no repair required to your wall.
I would use a 4 X 4 Pressure treated for the Fan Support.