What kind of connotation does the word "dump" generally have?

in that passage i would say the sentence which best describes the overall impact of the setting is when they mention the absence of people because it suggests that taking a walk at night is unusual.

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.