I'm on the the other side of the coin here on this one. I too found a snake in my wash room a few years ago. A brand spankin' new born ring neck snake. I'll have to find the picture to post. What a beautiful little thing. It is all black with a bright yellow ring around its neck. I had to look up what kind it is. I'm used to seeing garter snakes and copper heads, black racers and this one was new to me.
I do hope you find the critter and get it removed from your home without harm to anyone if possible. Just send it packing!
peace