Back in 2nd grade my friend got a small snickers bar at school that he discovered had a hole in the wrapper and a same size/shape hole also extending further into the candy bar. I recall it being a small squarish kind of hole, you could sort of see it going into the candy bar.

No idea if he did it himself or not, but he never admitted it. It could easily have been some part of a toy that poked into it.

After school we went to his house and cut it to pieces with a knife in his kitchen. It was an exciting adventure, we were eager to see what might be inside. Never found anything, though I'm not sure what we were expecting to find.

We didn't eat it either. But it did freak me out enough as a kid that for awhile after I would check for candy wrapper breaches.