Recently had wonderful remote controls by Harbor Breeze installed. Model # RCB-103L.
However, require very small 12v battery, looks like a AAA battery but about half the length and high voltage.

MSC Item Detail (http://www1.mscdirect.com/CGI/NNSRIT?PMPXNO=4660824&PMT4NO=87608199)

Or

Digi-Key - N403-ND (Manufacturer - A23CVP) (http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=393244&k=a23%20battery)

You could have an MSC office nearby. If you order in person, you don't pay postage.

Or locally at at a Radio Shack

http://www.radioshack.com/search/index.jsp?kwCatId=&kw=a23&origkw=a23&sr=1