If you are unable to placate the superstitious, you can perhaps speak the enemy's language (like in this clip from ZERT: http://www.youtube.com/watch?v=SGZX7oaDcQE ). For example, you can make mention of ghosts in the Bible (I'm sure the internet can help you with that), or perhaps push the nationalist button by mentioning the ghosts in the rich tradition of Czech folklore. Perhaps you can point out how you are ridiculing ghosts, and do not wish to give the kind of respect to the black arts that this woman seems to be giving. True Christians with Jesus in their heart have nothing to fear, and every story of the devil is a story about the need for Christ and his ultimate triumph. Why, you're practically doing God's work. But perhaps, you can just dismiss these charges as what they are: ridiculous. "Please, people, are we gonna be banning Shakespeare next because some ignoramus thinks Harry Potter is based on a true story."