The next logical question is; do you believe that Seth was an honest to god extraterrestrial consciousness? Or do you believe that he was simply a product of her schizophrenia?
Which is a fine point, although completely unrelated to what I asked. Let me try again.
Here’s John. John has, what you describe as, lower-order hallucinations. Heck, let’s acutally use your example and say John’s hearing voices that say “Hey, you chump! Eat my finger!”
Now, John is confused about these voices. He doesn’t tell anyone about them, for fear of being branded a ‘loony’. Now keep in mind that the voices seem absolutely real to him.
John goes to a bookstore. There, out on the shelf, is Seth Speaks. John picks it up, looks through it and realizes "Hey! Other people hear voices and this woman has done a lot of ‘reasearch’ and concludes that they are higher alien consciousnesses. I guess I am allright, I just need to find out what MY alien means when he says ‘Eat my finger!’
John, reassured, never seeks out treatment or counseling, instead choosing to focus on communicating with his alien voice. His schizophrenia worsens. Bad news all around.
That’s the real danger. Not skepticism.
**
Unfortunately, even the most scrupulous of scientists will can and do fall prey to self delusion. I don’t doubt that Jane Roberts, at some point, believed that Seth was real. What causes me to question her is the lack of any sort of peer review. Were Jane Roberts abilities ever tested by disinterested other parties? Have others been able to duplicate her techniques and contact Seth or a member of Seth people? Have those people been tested? Where is review? Where is the evidence? It’s simply cold fusion all over again.
I can’t say how I’d react. I don’t really believe you can say how you would react either. What would you do if a hand reached out of your computer screen right now and waved to you? What if a cow suddenly appeared in your living room?
I imagine the best I can say is that I would look for an explanation for the phenomena. How did it move? If the telekinetic moved it with his mind, how did he do that? Doesn’t action at a distance equal free energy and thusly violate the laws of thermodynamics? Can he do it again? What about his mind is different than other peoples? Is this a learned skill? Does the size of the object matter? Can he move things he cannot see but is aware of? How about things that he is unaware of?
I’d like to think that I would really enjoy something like that, just for the thrill of discovering and testing something new. 
Actually, If there can be said to be proof of God’s existence, the best evidence is most likely the lack of any evidence
But that again is just MHO.
I’ve tried to avoid your cognitive dissonance subthread, because it really doesn’t have very much to do with the main point. I agree with betenoir, the best defense against it is skepticism.