The word 会儿 means "a short amount of time." All dictionaries I have checked say that the correct pronunciation of this word is huìr (i.e., 4th tone). Nevertheless, I am fairly sure that I have heard it pronounced huǐr (i.e., 3rd tone) from time to time. It's especially obvious in constructions like 等会儿, where the speaker will pronounce 等 as déng in accordance with tone sandhi.
Is 会儿 ever pronounced huǐr in casual speech? Am I totally mistaken? If you're a native speaker, how do you pronounce it?