My work vehicle is a 1999 Cherokee SE. Lately my co-workers have been telling me that when I hit my left turn signal that sometimes the right turn signal in the back flashes too. I can not replicate this when I am parked. The dash indicator does not blink to show that the right signal is active but it does work for both directions. Any clues? I am thinking maybe clock spring, bad ground or mixed up wires. Also maybe a bad flasher unit?

I would start with the grounds. When they go bad all kinds of funky stuff can happen. JIM.