The logical fallacy called “Argument of Ignorance” is often used in the debating process. It appeals to ignorance, where a lack of contrary evidence is used to “prove” the argument is true because it has not been proven to be false or the reverse. The trouble with this assertion is that it excludes other options not only the choice between true and false. It could also mean that the answer is unkown or unknowable (Wikipedia). This is often used to shift the burden of proof. Here are some examples I ran into when debating with others.
-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.