Ad hominem as logical fallacy
A (fallacious) ad hominem argument has the basic form:
1. A makes claim X.
2. There is something objectionable about A.
3. Therefore claim X is false.
wikipedia
A fool is a fool is a fool, easily conned no matter what the subject.
If someone believes in UFO's and witchcraft, they probably also have poor judgement when it comes to politics, scams, and interpreting the significance of events that they only have a small bit of information on.