There are a number of services that I offer at TJ Cycles. One of the services available is Rear Derailleur Hanger Alignment. You can see below a list of possible faults in this area of the bike and the repair that will be carried out with this service.
Gears Not Changing Correctly Re-Align Rear Derailleur Hanger
Rear Derailleur Knocking Spokes
Rear Jockey Wheels out of alignment