I had this happening to me - After indicating, the stalk would return to neutral but the clicking noise would continue double time.
I ended up taking the assembly off the column to test and i could see it shorting/arcing across the circuits when the stalk returned to the neutral position. I pulled the assembly apart, found the area that was causing the issue and cleaned it up a bit (there was grease everywhere and burnt circuitry in there). Put it all back together and it seemed to fix it for a while, but I think the damage was done and later it would short again intermittently. In the end, I just sourced a replacement stalk and threw away my old one.
Try pulling yours apart - you might be able to get away with just cleaning it up