Things that should never be done
Whatever be the phenomena that the persons suffers or believes to be suffering, what he should never, ever, do is go to a witchdoctor, shaman, or similar, to do away with these phenomena (whether it be possession, evil eye, etc., etc.). And when I say witchdoctor, I am referring in general to seers, healers, psychics, necromancers, diviners, diabolists, mediums etc., etc. They should only go to priests and charismatic renovation prayer groups. Going to a witchdoctor of sorts will not solve anything, but rather could end up causing a malignant influence there where it didn't previously exist.
Nor should one trust these witchdoctors just because they have images of the Blessed Virgin or Jesus in their home or office or consulting room. A solution will never come from this remedy, but rather a worsening of the problem. All power in this matter was given to the apostles and whoever looks for a solution elsewhere in a mistaken remedy will find out that this world of invisible powers is real and that one should never have submerged oneself in it experimenting at one's own risk.