(If you need a bit more about these characters and reasons for questioning their houses, Wizarding World - formerly known as Pottermore - has published an article on it which can be found here!)
Every character, at one point or another, had personality traits that one might think of as belonging to a different house than they were part of. Are there any characters in the books that you think should have been in another house and if so, what house would they have been in? If there's a character you believe fits equally into more than one, share that as well!
Additionally, do you believe the sorting hat can make a mistake when it comes to deciding student's Hogwarts Houses or do you think it's decisions are always justified?
