I want to fit a remote control receiver to my ceiling fan.can you help and where to by it

Home depot, probably most large stores like that. Maybe Ebay?

Found this on Ebay:
Hampton Bay Ceiling Fan Wireless Remote 191-691 - eBay (item 280256576685 end time Aug-17-08 15:56:02 PDT) (http://cgi.ebay.com/Hampton-Bay-Ceiling-Fan-Wireless-Remote-191-691_W0QQitemZ280256576685QQihZ018QQcategoryZ20699Q QssPageNameZWDVWQQrdZ1QQcmdZViewItem)
Although it is out of stock, here's one from HD:
Hampton Bay Wireless Ceiling Fan Remote Control - T1&R1 at The Home Depot (http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&langId=-1&catalogId=10053&productId=100072901)

Hampton Bay ones are unreliable. See if you can find a different brand. Try any place that sells ceiling fans.