If the in-game stadium entertainment host isn't the job for you, and after what Photi said you would need to possess the same body style of a young Kate Moss to look good on the big screen.
Take heart, there are other positions.
The Marlins are currently hiring inside sales representatives (seasonal) and receptionists (gameday), as well as personnel for their Game Presentation and Events department. Team representatives will also be interviewing candidates for internships in the following fields: broadcasting, community affairs, community foundation, corporate sales, game presentation and events, marketing, media relations, baseball operations/player development and sales.
I'm sure they pay next to nothing, the way most internships do, but they could be fun.