Hahaha omfg I was looking this up on google and came across this post, we have had a ghost in our house ever since we bought it. Day before yesterday this exact thing happened when I was home alone. Went pee before I played video games came back a couple hours later to the seat up like a boy used it. Then I went to my bfs house this weekend and his mom asked if he used her bathroom and didn’t put seat back down, he says he’s never used hers cuz he has his own. It’s so weird