What is the ruling on slaughtering in Rajab to ward off harm from jinn, with the intention that it is for Allah?

Slaughtering as an act of drawing closer to and humbling oneself before Allah is an act of worship that may not be directed to other than Him. Whoever slaughters for other than Allah, as an act of drawing closer and glorification, is a disbeliever and an apostate. If the slaughter is for jinn to appease them and prevent their harm, then this is major shirk (polytheism) that expels one from the fold of Islam. However, if the slaughter is for Allah to repel the evil of the jinn, it is not disbelief that expels one from the fold of Islam, but rather minor shirk, because it attributes causality to something that is not a cause. As for what the questioner claims about the jinn harming him if he does not slaughter, that is from the whisperings of Satan. Allah has given the jinn power over him because he turned to them and relied on them. Had he truly put his trust in Allah, Allah would not have given the jinn any power over him.