The numbers here are significantly lower than I would expect for interest, but about on target for the number of people who significantly believe in such things. The number for UFOs used to be at 40-50%, but studies with those numbers did not differentiate causes (such as UFOs being extraterrestrial. And in fact, some UFO believers would not have answered yes to that question, looking to other potential origins.
Here are some of the results from The Baylor Religion Survey's look at America's beliefs in the paranormal. The study included 1,721 nationwide respondents.
75 percent believe alternative treatment is as effective as traditional medicine.
52 percent believe dreams can sometimes foretell the future or reveal hidden truths.
37 percent believe places can be haunted.
28 percent believe it's possible to influence the world through the mind alone (telekinesis).
25 percent believe some UFOs are probably spaceships from other worlds.
20 percent believe it's possible to communicate with the dead.
18 percent believe creatures such as Bigfoot and the Loch Ness Monster will one day be discovered by science.
13 percent believe in astrologers, palm readers, tarot cards, fortune tellers, and psychics.
Source: Baylor Institute for Studies of Religion