Truck of shredded Pennsylvania "mail in" ballots found in back of truck trailers

Recently a man found what looked like the leftovers of the shredding of an unknown amount of Pennsylvania ballot forms. Apparently these are applications for mail in ballots. The man says there are more trailers that have the same thing in them. The question is, why are all the mail in ballot forms being shredded in the back of truck trailers. Of course, the interesting thing about a truck trailer is it can provide a temporary "hideaway" to do something while in between locations. You can drive to a location - stop - do what you need to do - then continue.