Is it permissible to pray behind an imam who seeks the help of Muslim jinn to treat the sick and those afflicted by sorcery for a fee, knowing that he is religiously committed and of good character? And if going to another mosque is difficult for us, is it permissible to pray at home?

It is permissible to take a fee for ruqyah (exorcism by means of Quranic recitation), based on the Prophet's (peace be upon him) saying: "Indeed, the most deserving thing for which you take a wage is the Book of Allah." As for seeking help from Muslim jinn in ruqyah or other matters, it is not permissible. The Imam should be advised regarding this, and you should not abandon praying behind him, as prayer behind a fasiq (transgressor) is valid, even if it is more preferable to put someone else forward.