Missing T-shirt Found Two Weeks Later

Fucking hell, I'm a convinced skeptic myself, I don't believe in paranormal shit at all, same as my mother, who I live with, so here's the story.
We clean the house regularly, every 3-4 days. In the hallway there's an ordinary IKEA coat rack made of 4 poles, on wheels. So one time, leaving for school, I threw a T-shirt on it, an ordinary grey one, and went off to study. When I came back, the T-shirt wasn't found, neither by me nor by my mother, we cleaned 4-5 times since then, completely rehanging, sorting, moving the rack. And then two weeks later, calmly having breakfast in the kitchen, we noticed something grey, we walk over, turn on the light, and fucking hell, that same T-shirt, we looked at each other in shock, tried for a month to figure out how, no fucking ideas, still don't know what that was (happened half a year ago P18)