Changing a single-gang box to a double-gang box isn't all that
easy. It could be done, I guess, but most electricians would
try another approach... just add another single-gang "old
work" box a few inches away and connect it to the
This can only be done
if there is not already a big tangle of wires in that existing
box. If there is only one or two cables leading into that box,
you should be okay. If there are 3 cables, you may not be
allowed to add any more. The National Electrical Code has
restrictions on how many individual wires are allowed in a box
of a given size. Their intent is to prevent over-heating of
wires inside the box. I know this rule is violated a lot by
do-it-yourselfers, but that doesn't make it right or safe.
If I had to change to a
double-gang box I would remove the old box by cutting the
mounting nails with a metal cutting blade in a reciprocating
saw. This is done by shoving the blade between the box and the
stud. A little bit of drywall might need to be cut away to
find the stud. Of course, the circuit breaker needs to be
turned off and the outlet needs to be removed so the ends
of the wire are just dangling. Caution needs to be the rule
here... it is possible to cut the insulation of a wire nearby.
I would shine a bright flashlight in behind so I could see the
location of any cables around the box. A hand-powered hack-saw
is safer, I guess, because you can tell if you are hitting a
cable. Once the nails are cut I would pull the box out, with
the wires just sticking out of the hole in the wall.
Next I would get a two-gang
old-work box, but only the type that has the two little
rotating clamp tabs. I'm not sure this can be communicated in
an e-mail. I think there are pictures of an old-work box
somewhere on HammerZone.com. The only type I use are the blue
Carlon brand with the two rotating clampy things. These are
available in single and double width, maybe wider. But... you
need to be very careful when cutting the opening in the
drywall. If you cut too big it's all over but the cryin!
With the proper hole for the
2-gang old work box (I always test-fit the box) I would put
the wires in the box and mount the thing. Then I would restore
the wiring the way I wanted it.
This is a project for someone
who has a decent level of electrical experience.
Note that code absolutely
FORBIDS using a dimmer to supply power to an outlet, even if
the intended use of the outlet is for a dim-able light
fixture. There is always the chance that some motorized
appliance can be plugged in, and motors WILL NOT work properly
if a dimmer is used. In fact, that is a good way to destroy a
motor, and possibly overheat a motor and cause a little fire.
Some under-cabinet lights are
meant to be hard-wired, that is where the cable is connected
inside the fixture. The package usually says "Direct
Wire" when this is the case. These are the only type of
lights that are approved for dimming.
Bruce W. Maki, Editor.