In Quantum Physics it is possible for two elementary particles of opposite charges to spontaneously form. However these particles normally annihilate one another.

If these two particles were on the edge of a black hole the negative particle could be drawn into the black hole. The positive particle would escape and would appear as radiation from the b/h. As well, after an infinite amount of time, the -ve particles would annihilate the matter in the black hole and cause it to explode.