Headlight switch issues - parking lamp position

[62lwbc10]

Hey all I'm just getting around to rewiring my truck. I'm using all new period Correct harnesses I've wired the truck before Ising these same new harnesses performed the frame off restoration and everything was fine. Now that I'm putting it together two years later I'm having some issues. When I put the headlight switch into the parking light position, the instrument lights flicker and there is some cracking electrical sounds. Not good. When I do this in the dark and look under the dash I see some blue sparks in the headlight switch and I see that the spark seem to be coming from the slider that gets actuated when the parking light position is put in place. Everything seems to be wired correctly not sure what the problem is. The switch otherwise seems to be fine. When the headlights are put on there is no snapping sounds the headlights work and there are no flickering instrument lights it seems only to be when the parking light position is used. Could improper wiring at the parking lights themselves or bad grounding cause this.? I wouldn't think so. I hate to get a new switch and have the same thing happen if I've got something wired wrong. And if you thought it would be helpful thanks in advance