The Uncanny itself ('Das Unheimliche') refers to the conflict between something appearing simultaneously familiar and unfamiliar. The end result of these instances is that the observer experiences a strange familiarity, where usually there would be none. He or she is both drawn to and repulsed by the object, creating the feeling of dissonance. The result of this dissonance is, more often than not, a subsequent rejection of the object in question, due to the unsettling nature of the Uncanny.
Horror writers (or Weird writers, or any speculative fiction writers who want to creep out their readers) should have a look. It's a good discussion and analysis.