At the latest qep'a', {mIS} and its variations were confirmed to refer to mental confusion. If by "great confusion in the street" you mean to emphasize that nobody knows what's going on, then {mIS} sounds like it would work. ("Much Ado About Nothing" was once translated as {paghmo' tIn mIS}, literally "the confusion is great because of nothing", although this wasn't done by Okrand and was also done before the latest qep'a'.)

It is probably not usable in the sense of "mixing up one thing with another". For that, you could perhaps try a phrase with {ngu'Ha'} "misidentify" or the like.