A couple of examples:
It's been taught that you can suffer demon possession if you have something in common with the demon. But if you change your heart so that you don't have anything in common with the evil spirit, the demon can't possess you, and you won't suffer illness.
I've seen a video where someone is fighting against what they believe to be a possessed area, using shofars, kettledrums and a tuning fork! Apparently, the tuning fork was needed to "level the area", whatever that means - somehow to remove evil.
I've also heard a sermon where it's been taught that the reason you can't get an increase in your income (that is, get rich) is that there are demons who put a cap on your finances. They claim that you are required to follow some steps to overcome the demon, in order that you can position yourself to prosper.
Still more, Jennifer LeClaire wrote a whole book on how to defeat "water spirits":
https://www.amazon.com/Spiritual-Warriors-Guide-Defeating-Spirits/dp/076844294X
She's also preached a lot and very detailed information on the "Jezebel spirit", nowhere to be found in Scriptures. She, and others, promote their own seminars, courses and books that will help us overcome demons - in exchange for money.
I'm happy to go into details on why these ideas are problematic, but hopefully, it should be self-evident. What is common to all of these is a real lack of Biblical substance. Christ is not preached. The Gospel is forgotten. Its main focus is on what we need to do to overcome illness and evil, when Scripture nowhere promises that Christians will be rich and healthy.