There are some sheikhs who treat people by reciting Qur'an and other Dua'a and in return take money for it.
Is such a practice permissible in Islam?
Treating people from evil eye, Black Magic, Demon Possession and other such sickness is called Ruqyah. It is permissible in Islam to seek cure for it by using Ruqyah from the Qur'an and the Sunnah of the Prophet (peace be upon him) only. It should not be associated with calling another being other than Allah and it should not be mixed with strange, unknown words.
Giving something to the person who performs Ruqyah is also permissible.
Narrated on the authority of Abu Saeid Al-Khudry (may Allah be pleased with him), he said, "Some of the Companions of the Prophet (peace be upon him) came across one of the Arab tribes, but they refused to extend to them hospitality. In the meantime, the chief of that tribe was bitten by a snake or stung by a scorpion; they asked them, "Have you got any medicine with you or anybody who can treat with Ruqyah? The companions said, "You refused to entertain us, so we will not treat your chief unless you pay us for it." They agreed on a flock of sheep, so one of them the companions recited Umm Al-Qur'an (Surah Al-Fatiha), then gathered his saliva and spat on the snakebite. The cheif got cured and his people presented the sheep to them, but they said to themselves, "We will not take it unless we ask the Prophet (peace be upon him) whether it is lawful to take it or not." When they asked him, the Prophet (peace be upon him) smiled and said, "How did you know that Surah Al-Fatihah is a Ruqyah? Take it (the flock of sheep) and assign a share for me." (Bukhari)
From this Hadith we learn that the opening chapter (Surah Al-Fatiha) can be used for treating evil sicknesses and other such diseases, and it is allowed to give something in return to the person who performs it.
Hasad (destructive envy) means wishing that a blessing that Allaah has bestowed on the envied person be taken away.
The evil eye is a look that is believed to be able to cause injury or bad luck for the person at whom it is directed for reasons of envy or dislike, with the intention of inflicting injury or bad luck by such an envious or ill-wishing look.
and its existence is confirmed by the Qur'an and Sunnah and is agreed upon by the scholars. It is a reality and a truth, and it affects a person only by Allah's will.
is where the demon (jinn, evil spirit) takes control of the human body and controls the mind of the person into performing actions that one may not perform in normal circumstances.