-When one spots many UFOs (Unidentified Flying Objects) and then conclude that they are Alien spaceships.
-That if one cannot proof there is no God, it is evidence that there is one.
-That without evidence that a miracle has not occurred, it is proof that it was one.
-That if you cannot prove that a psychic talked to the dead is fakery, it must be a true ability.
In all of those cases, it is a “shift of the burden of proof”, When one makes an assertion then it is up to that person making the claim that they have evidence of their conclusion, not the other way around. In all of these cases the answer could be “unknown” or “unknowable” and therefor no conclusion can be drawn either way.