Dash lighting slowly come on their own?

Sorry it took me so long to get back. Life's crazy like that. I grabbed one at the junk yard. I was there for something else and saw this car there with the dash already apart, and the switch looked new. Put it in no change. I also realized that the radio and center console lighting does dim and brighten as it should at all times. So I'm thinking there must be a power wire going from that switch to the odometer/PRNDL. The issue would be in that wire or in the cluster itself. I'm leaving towards the cluster itself. Maybe cracked solder joints. Before the solder would expand with heat as the car warmed and eventually make good enough contact to work. Eventually the cracks became too large.

Does that sound plausible?

The ground wire seems like a viable option. I'll check that. If I'm reading correctly, it should be the one going to the firewall, below the dash, left of the steering column. After that, I've already got half of the dash apart because I'm swapping the stock radio out for one with Bluetooth that I got out of a parts grand am, so it's only a few more screws to pull the cluster and look at the solder joints. If I see something there, I've got a tiny soldering iron and some rosin core solder that I've used on laptops that might do the trick.

As for the dome light, I'm not terribly worried about it. I keep forgetting to get a bulb to check that possibility, even though I'm in AutoZone weekly because I use and abuse my cars heavily (they're proper workhorses).

But this one I kind of want to bring back for use as a daily and a backup workhorse.