Why would a turn signal switch need a ground? It simply routes voltage to the front and rear bulbs and puts them in series with a flasher. The ground happens at the body sheet metal downstream from the light filaments. If there is a ground wire in the switch harness for some unknown reason, it can be attached anywhere under the dash to the steering column or any other part of the body metal.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!