Growing up in Denair, Emily Wynn had an early interest in live theatre and earned her college degree in business administration, so it may have seemed odd to her that she was making her living earlier this year by riding around in ambulances. Wynn is part of Lincoln Square Productions, which is behind “Boston EMS” airing on ABC. Now in its second season, “Boston EMS” gives viewers an up close look at the work performed by the men and women that serve as emergency medical technicians in the Boston area. It was this same group that responded to the critically injured Boston Marathon spectators three years ago when the bombs went off.