How can you get ramsay - hunt syndrome?

Viral cause: Ramsey-Hunt syndrome is also termed "Herpes Zoster Oticus", due to fact that eruption can be seen within external auditory canal, associated with facial paralysis on that side. Cause is the above virus.

There are 3 types: Type 2 is the most common, referring to Zoster (reactivated chicked pox in a nerve) involving the nerve in the ear as well as the same side of the face. If you want more complete details you can try Wikipedia.