I dont know about Sheidim, but below is what the Rambam says about Kishuf (Madda Hilchos A”Z 11:16)
?????? ???? ???? ???? ??? ???? ?? ??? ????? ??? ????? ?????? ???????? ????? ?????? ??? ?????? ??????. ???? ???? ?????? ??? ????? ??????? ????? ?????? ??? ??? ?????? ?? ?? ??? ????? ???. ????? ?? ?? ??? ????? ??? ??? ??????. ????? ?? ????? ???? ??? ??? ???? ???? ?? ??????? ??? ?????? ????? ???? ?? ?? ???’.
?? ?????? ?????? ???? ?????? ??? ????? ???? ??? ??? ???? ???? ??? ????? ????? ???? ??? ?? ?????? ?????? ???? ????? ????? ??????? ???? ???? ?????. ??? ???? ????? ?????? ???? ???? ?????? ?????? ??? ??? ?????? ????? ???? ???? ???? ???? ??? ??? ???? ?????? ??? ???? ???? ????? ?? ???? ???? ?????. ????? ?? ???? ???? ???????? ?? ?? ??? ?????? ???? ???? ?? ?’ ?????
So it is apparent that he didnt beleive that there was ever such a thing as Kishuf.