its hard to get a part for a fan type light, your going to have to take the light down to fix it , if you can get a part that will fit it anyway , i would just replace the light with a new one , just have it taken down , and put up a normal light, if your going to see if your lighting shop can get it fixed for you or give you the part, or get a new fan light, it has to come down anyway...
h
February 2011