"Uh, uhm, uh.....sorry Ma'am. Have a good day." And off they go the the correct house.
I understand that in some severe situations they may need to burst in without a knock, but that ought to be extremely rare, instead of common, like it seems to be now. We have lost control of the niceties of civilization, and if we want to remain free, we have to regain control of them and the fascists who argue agains them.
The justification for "no knock" warrants go back to English common law.