The Special Constabulary are volunteer police officers. Also known as 'specials' they carry out policing duties in their spare time. They come from all walks of life - they are teachers, taxi drivers, accountants and secretaries, or any number of other careers.
People join the Special Constabulary for many different reasons. You may want:
to give something back to the community
to learn new skills and gain valuable experience
to challenge yourself
to learn first-hand about the police force before committing to a full-time job there