One of the things I have considered, but I think it would be extremely difficult to pull off successfully, is a "conspiracy theory" book club.
From what I can tell there is a basic societal confusion with the term "conspiracy theory" itself. For some people, the term refers to a theory about conspiring that could be true, false, or preposterous, while for others the term automatically refers to a preposterous theory.
I was thinking a book club could formulate a list of criteria to run a conspiracy theory through to test its plausibility and then read "conspiracy theory" books (fiction probably safer) as test cases.
Another idea would be to take a book like "The Crying of Lot 49" to discuss the idea of conspiracy theories and why they arise.
All of this would probably only work with a highly skilled facilitator though!