What are some unexplained phenomena that people have reported?

 Born in 1813, a woman named Emilie Sagee had the ability of bilocation, from the age of puberty. Throughout her life, she struggled every day to escape from her own doppelganger, whom she couldn't see at all, but others could.

She was the boarding school teacher during 1845 in Latvia, France. One day she was writing on a blackboard, the students saw two Sagee, the one by the side of the other. They were exactly alike and showing same gestures, only that the real Sagee held a bit of chalk in her hand, and did actually write, while the double had no chalk, and was only imitating the motion of her hands. Within few months, similar phenomena were still repeated. The double sometimes imitating the original exactly, and sometimes not same.

A popular theory suggests that Sagee was being haunted by her own double walker and there are a number of superstitions surrounding the exact double of another person, and most of them involve in bad luck or impending death.