Ehhh i think it's possible; my dad told me a story about it once. He said when he was a teenager he and his friends decided to try it, they lit candles and everything. They asked a few questions, none of which he could remember, but after a while, he said the toughest and most rebellious of their 'friend' group suddenly walked out. When he confronted him about it, he said whilst trembling that he saw an eye in the candle...
Idk, i believe it, but i'd never try it myself. I feel like there's a lot more to this world than what we think, but that could just be me being cryptic ^_^