I had originally wondered that about mine, the signals horn, all that works perfect. I put a new iggy switch in, new turn signal cam and harness in, made sure that rubber sleeves they were in were effective, not rubbing against anything. My amp gauge is bypassed (both on one post) to avoid any issues there.

It's not electrical guys, nothing in the column can get that hot. I'm sure it's heat coming up the steering shaft. There was a cheesy nylon bearing down there when new. They only last so long and then fall apart and let engine compartment heat to rise up into it and into your car.

Need to positively seal it up to fix your problem.
Bill from A&M Hitech sells new plastic bushings to go down there, that's the correct way to fix it.

My 74 challenger has this one year only metal bearing down there which is very nice compared to the plastic deal. As you can see no air can go up there and my lower steering shaft is supported well.
Actually this is my 71 column that I used a 74 bearing on.

I see the plastic bearing in there, it's somehow worked its way out of that clip and about 3 inches up into the shaft. When i pull it I'll relocated it to original location.