Do they use general anesthesia for wisdom teeth removal?

Yes. Yes. General anesthesia is routine used by board certified oral & maxillofacial surgeons. Make sure your doc is an oral surgeon.
Maybe. General anesthesia would be used in a hospital setting. In an oral surgeons office, they would use conscious sedation, which means you will be breathing on your own, but will have no memory of the procedure. General anesthesia requires intubation and a machine that breathes for you.