Doppelganger (noun)

1. A ghostly double or counterpart of a living person.
2. A lookalike or person who closely resembles another.

Origin:

German, from doppel- (double) + gänger (goer).

Examples:

1. People say that everyone has a doppelganger somewhere in the world.
2. The actress was mistaken for her doppelganger several times in public.
3. The painting of the doppelganger haunted the museum for years.
4. The doppelganger was so realistic that even the family members couldn't tell the difference.
5. Many people believe that encountering your doppelganger is a sign of bad luck.