These myths suggest that religious icons, religious rituals or holy and powerful words will force a malevolent spirit from a home is steeped in the folklore of the Middle Ages. What magical powers do these words have. The answer is no. Worlds alone cannot change the course of a river nor move mountains. Words can help us understand about the world within which we live.
Words have no effect or power upon the spirits of the dead.
Let us consider why a spirit may remain in this earth plane as a malevolent spirit. Consider a person who allowed his vices to rule his life. This person succumbs to the baser instincts in life and relies upon his need to feel good by outside stimulation. His spirit is debased and resides in the lowest levels of the spirit world upon his death. That spirit has not evolved into a higher life form but has retained the level it was at death.