I received a ticket for an illegal right turn (I didn't notice the sign) and received a ticket turning from Bayview right on to Proctor in Thornhill. The officer wrote on the ticket that the offence was at Bayview/Proctor in the municipality of Richmond Hill? Does this have any case since the location of the sign can be in question? Thought I would ask before sounding stupid in court. The officer was very nice and did suggest that I bring the ticket to court but I'm not sure what she meant by it.

An incorrect offence location is not what's considered a "fatal" error, where the ticket is simply withdrawn. When the officer suggested you bring the ticket to Court, she probably meant that if you have a first attendance meeting with the Crown, they'll offer you a reduced fine and/or less serious charge in exchange for a guilty plea. Some municipalities have bylaws that cover prohibited turns, and the Crown will frequently allow you to plead to the bylaw charge instead of the Highway Traffic Act one. Be warned however, you can still receive demerit points for offences relating to turns even with bylaws.

If you actually went to trial, I'm not sure how much luck you'd have arguing the location. The main problem is that the location is something that can easily be amended if the Crown is aware of the error.