This answer demonstrates that the messiah must be human. See also Sanhedrin 98a in the Babylonian talmud, which -- in the midst of a discussion of signs that the messiah has come -- calls the messiah the "son of David" several times. "Son of David" -- that is, a Jewish man descended from King David. A man, not a supernatural being. From the Soncino translation:
R. Johanan also said: The son of David will come only in a generation that is either altogether righteous or altogether wicked. ‘in a generation that is altogether righteous,’ — as it is written, Thy people also shall be all righteous: they shall inherit the land for ever. ‘Or altogether wicked,’ — as it is written, And he saw that there was no man, and wondered that there was no intercessor; and it is [elsewhere] written, For mine own sake, even for mine own sake, will I do it.
And also this (ibid, 98b):
Rab Judah said in Rab's name: The Holy One, blessed be He, will raise up another David for us, as it is written, But they shall serve the Lord their God, and David their king, whom I will raise up unto them: not ‘I raised up’, but ‘I will raise up’ is said. R. Papa said to Abaye: But it is written, And my servant David shall be their prince [nasi] for ever? — E.g., an emperor and a viceroy.
But, you might say, maybe angels are also human so Michael could still qualify? But angels are not humans and cannot be. One proof of this is in the g'mara on Shabbat 88b-89a, which relates how when Moshe ascended Mount Sinai to receive torah, the angels in the heavenly court challenged God. "How can you give Your holy torah to mere humans?" they asked. God told Moshe "answer them", and Moshe proceeded through several of the commandments, asking the court if they were capable of fulfilling them. Do you work, that you need to refrain on Shabbat? Are you capable of forming the intent to murder? Do you have relations that you could commit adultery? Do you even have fathers and mothers that you could honor them? In the end the angels conceded that the torah belonged to men, not them. From this we learn that angels are not men, else they would have been able to claim torah for themselves.
How do we know that Michael is an angel when the book of Daniel, where he is named, does not say so explicitly? We know this from the midrash. Bamidbar Rabbah 2:10 names the four "arch-angels" and describes their functions. This is not their only mention in rabbinic writing; for example, B'reishit Rabbah records that Michael was one of the angels who visited Avraham (specifically the one who announced the birth of Yitzchak). This article provides more sourced details while remaining accessible.
It's hard to prove a negative; quite possibly some Jew, somewhere, has believed what you ask about. But it is not a belief that has survived in Jewish sources and, since it runs counter to core Jewish theology, it would need to come with a pretty strong supporting argument.