It's considered proper (though often ignored) to write ください in 待ってください and 下さい in 赤いのを下さい, i.e. Kanji as a main verb and kana as an auxilliary. But a thought came into my mind: in お待ちください, is it an auxilliary and thus ください, or is it rather a main verb wanting the Kanji?
(Of course, using the kana would be correct in any context. I was just wondering if お待ち下さい was correct.)