There's a number of claims about Sagan having wooish beliefs. Richard "face on Mars" Hoagland is famous for taking Sagan out of context or trying to co-opt Sagan's authority.
Then, near the end of his life, Sagan underwent his final public change on the subject of Cydonia: in a 180-degree turn from the PARADE article, he went out of his way to separate the "Cydonia investigation" from the other, "pseudo-science" targets of his last published work, "The Demon Haunted World." In this final written statement of his life, Carl Sagan deftly contradicted all his previous "official" positions on Cydonia: pointing out that the Cydonia investigation, as distinguished from most "extraordinary claims," stood apart -- by having the one essential precept of "good science" … it could actually be tested. He concluded his "about face" by arguing that, as a clear "scientific problem," Cydonia deserved to be fairly tested in the coming years … via a veritable fleet of new missions then heading back to Mars …
Which, curiously, is precisely when NASA (and Russian) missions to the Red Planet literally began to disappear …
http://www.enterprisemission.com/MTM.htmJournalist Joel Achenbach, in Captured by Aliens (1999), noted that once Sagan achieved superstardom with Cosmos, he became the public lightning rod for both the science and the pseudoscience of extraterrestrial life. As the “keeper of the gates” who effectively defined the border between science and pseudoscience, he was actively courted by many fringe figures who sought in his blessing a legitimization of their interests or beliefs. As an example, Achenbach reported this interview with Richard Hoagland, the popularizer of the “Face on Mars.” Hoagland explained that in a public meeting in 1985, Sagan commented that those planning NASA missions to Mars should be open to discovering the unexpected. According to Hoagland, when Sagan made these remarks, he briefly made direct eye-contact with Hoagland, who was in the audience. In the weird world of pseudoscience, Sagan’s innocent comment was interpreted as a coded message encouraging Hoagland to pursue his advocacy of an artificial origin for the Face—which he continues to this day, in spite of all the evidence to the contrary. (See some of Sagan’s thoughts on the Hoagland/Mars Face matter in “Carl Sagan Takes Questions: More from his ‘Wonder and Skepticism’ CSICOP 1994 Keynote,” SKEPTICAL INQUIRER, July/August 2005.)
Sagan’s role is especially interesting because he himself was accused of straying beyond the limits of proper science in his pursuit of evidence for life on other planets and his defense of SETI. As Achenbach argues, it was precisely because of his apparent open-minded attitude toward fringe topics that many on the fringe became so bitter when Sagan turned against them.
http://www.csicop.org/si/2007-01/sagan.htmlThere's also a spiritualist type who purports that Sagan was a believer in his own special brand of mysticism and psychic powers for a good portion of his life. Can't find that reference right now though. Sorry.