You are not allowed to have AC power and low voltage (cable/phone) in the same box unless there is a divider that isolates them.

If you don't have such a box then the best thing to do would be replace the gang box with 2 separate ones on each side of the stud.

If you do have a divided ganged box then there are a couple of options.

Get a Duplex/Blank cover (Leviton #86008)

http://www.twacomm.com/catalog/dept_id_811.htm?sid=D13092E5AEAF32BB5D63CB2620F7BF4E

And drill a hole in the blank side and install the F connector in it.

Or get a F connector in a Decora frame (F-1D)

http://www.happymedium.com/nilecon3.htm

Or get a Decora QuickPort Frame and install an F connector module in it.

http://www.hometech.com/techwire/frames.html#41642W

What can I use to divide the box? A piece of plastic? Both lines also run beside each other down the stud to the basement.

Carlon makes a 2 gang box where one side is closed for 120V wiring and the other is open for low voltage wiring. They also make clip-on low voltage boxes that attach to a single gang box. Check the local big box or an electrical supplier.

All that being said, I would go with two separate boxes, then the wall plate issue is resolved.

Claron also offers a one piece box where you can then insert a divider. Last item on the page.

SCDIV

Orange Super-Blue Divider

http://www.hometech.com/techwire/wallboxdual.html

If you box will take that divider you are ready to go.

Otherwise, since you have a finished wall, you can cut out the old box. Use a metal cutting sawzall to a single end holder for a hacksaw blade.

Most likely you will endup leaving the old box in the wall as it nailing tabs will keep it from coming out.

Then get one of the dual voltage versions and cut off any nailing ears so that it will fit through the openeing.

Then attach it to the stud using a screws through the side into the stud.

Went to weber electrical supply today and told him about the switchplate and he brought me back a plate that had the 110 on one side and the rectangular hole on the other and then another cable plate(two piece design with rectangular insert) so all I had to do was unscrew the cable insert and screw it into the the other plate and now I have cable and 110 on a double plate. Vest of all it only costed me 2.59. I could not believe how much cheaper this place was compared to home depot. Thanks for your help everyone. Shawn