The part of Electrospasm which was once Harold Smears, murderer, was all but burned from him upon the electric chair. All that's left is a polite, apologetic spirit of punishment.
Electrospasm is a wraith. In life, he was a convicted murderer named Harold Smears and was the last criminal to be sentenced to the electric chair before Gravenville stopped using it. Given the severe burns on his body, it's likely that Electrospasm's execution was botched. His spirit now resides both in and on the chair that killed him, feeling he needs one last good jolt to be free.
Electrospasm can be unlocked in The Unusual Suspects or Ghostbreakers. To free him, he needs to be badly shocked again. This can be done by binding a water elemental to the nearby sink, having them fill the room with a Flood, and having Electrospasm use Spark. The resulting electricity will not only be enough to free him but will cause the building's lights to flicker, scaring all the mortals present, especially those afraid of the dark. If he's not freed in The Unusual Suspects, he'll be locked in an ESD cell in the Ghostbreakers mission.