This is why all good home inspectors should open electric panels. If your past home inspector didn’t, he did you a disservice. I open every panel cover because I never know what type of electrical deficiencies I could find inside them.
For instants, this week was this heavily breaker that had caught fire in the part without the homeowner knowing. This double tapped breaker was charred from a past internal electrical fire and many other breakers were severely corroded from panel moisture. This type faulty wiring is how houses burn down!