On three occasions now, I have opened food packaging (box of oatmeal packets, fruit cups, sugar packets) and found religious tracts about salvation. The first time, I thought, "Wow. Some nut is really going through the store and putting these in fruit cup packages?" The fruit cup packaging didn't bother me so much - the cardboard "wrapper" is fairly open and you can easily slide paper in between the cups. The oatmeal and sugar were obviously opened at a seam and taped shut, which I didn't notice til I was back at the office.
That store manager is getting an email.