What does Alfred Hitchcock say is the difference between mystery and suspense?

“Mystery is when the spectator knows less than the characters in the movie. Suspense is when the spectator knows more than the characters in the movie.” The fact that two terms often considered synonyms have actually two opposite definitions may surprise, but once you go deeper the difference is even enlightening.

type of error:

the error in the sentence is a "dangling modifier". a dangling modifier is a phrase, word or clause that "dangles" because there is not target to modify. in this case, "after mopping the floor" is the dangling modifier since it has no word to modify. the noun "house" cannot mop the floor; therefore there is a mistake in the writing of the sentence.