Short in wiper switch or dash?

[sgr60]

So this is a weird one...

Was going to take the truck out for a drive today and when I turned on the wiper switch, rather than turning on the wipers, it illuminated the right turn signal indicator on the dash. What!?

I assume there is a short somewhere - but I wonder the best place to start looking is. I pulled the steering wheel and looked as best I could at the components in the column, couldn't find anything that looked suspicious there.

I tried playing with some other controls to see what else might be going on, and I found another weird one - when I turn the dash dimmer switch all the way to the left - just before it turns on the cab light - it also illuminates that right turn signal indicator.

For what it's worth, when the turn signal indicator light is on and I turn on the right signal, the flasher does override it and cause the indicator to flash as normal.

I'm completely lost - I'm thinking maybe I have to pull the dash and check for a short back there? I've looked from underneath, can't see much - all of the connections appear to be solid, but I can't really tell what's related.

Any thoughts?