Well, this one's not quite as graphic. Another refrigerator, another apartment formerly occupied by a person with a cat. I think.
This time, when dad pulled out the fridge he found a cluster of crumpled up papers. Grocery receipts, notes, post-its, etc. made up this little collection of things that had been swatted, batted or maybe just simply placed beneath the refrigerator.
I'm guessing that, as with the poop dad found, these balls of paper were someone's toys that found their final resting place under the fridge.
If you look at this photo and just visualize each crumpled piece as a ball of pee or log of poop, you will have a good idea of what that other situation looked like.