Well, never, of course. But these two words are quite often confused by English-language learners. It makes sense really. The two words obviously sound similar, and that’s particularly true for speakers of languages which don’t make such a distinction between the ch (/ʧ/) and k (/k/) sounds. And of course it’s logical to create an association between the two things: where else are you going to keep your chicken?
When is a Chicken a Kitchen?