Is there a way to have what you saw (her going into other people's offices and unplugging their computers) documented? The people whose computers were unplugged could also sign informal documents, stating their computers were tampered with. This could go in OW's employment file, and it could be used to fire her if she continues crossing boundaries and being unprofessional.
Like someone else said, in most work places, that type of tampering would be a serious offense.
Sounds like it is a good thing your WH is looking for work elsewhere. His work place is a very dysfunctional and unprofessional environment.