What should I do with this Mus'haf that was found in a drawer with traces of mice, given that burning, tearing, or burying it is impossible?

The meaning of the word "al-qajar" is not clear. However, whoever finds a Mushaf (copy of the Quran) or a page from it in an inappropriate place must pick it up and remove it. If it is no longer readable, there is no harm in burying it or burning it to protect it from desecration. It has been reported that Uthman (may Allah be pleased with him) ordered the burning of all copies of the Quran other than the one he compiled, and none of the Companions objected to that. Tearing (the pages) has the same ruling as burning in protecting the papers from desecration.