Amtx44
No idea, but I am also constantly finding things like this. Not to be crude, but they almost look like urine on pieces of dried up toilet paper...? I find them everywhere around the house! And I think I'd remember scattering urine soaked TP all around so there's no way that could actually be it. Lol. It's got me wondering if it could be fungus or mold. Would definitely like to get some answers on this as well.