I used to use Ouija boards really regulary, and was very confident that I was contacting spirits. As time went on, I turned to trance writing (for greater efficiency), and then to seances and intentional posession.
Eventually, as I aged, I developed a more analytical mind and, because I still believed, I set up experiments to prove that all this stuff was legit... Of course, the results were never what I had hoped for. Eventually the Ouija stopped working completely, and the seances and trance writing started to really feel like I was making it up.
In the end, I think I was making it up. My friend and I were subconsciously pushing the oracle, and there never was a spirit named Amaden who temporarily inhabited my body.
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Consider that if you were really talking to people who once lived on Earth, it would be pretty easy to prove that the experience was real. Nobody has claimed The Amazing Randy's million dollar prize yet (
http://www.randi.org/research/index.html), so it's a safe bet that that stuff is bogus... But it's also highly entertaining and it beats running around the streets at night, so don't let me discourage you from doing it. It also taught me a great deal about myself.