Gas leak, 1996 dodge neon?

1996 Dodge Neon. steady gas leak, basically emptying most of the tank in a few hours. The car wasn't used for about a year. We put about 5 gallons in an empty tank, and before I finished cleaning the windshield with the squeegee I noticed significant leaking around the center of the car. possibly closer to the back. Previous owners were doing minor work to the car. I'm wondering if they installed something incorrectly?? Could it be something as easy as a fuel filter?? *hoping* I just want to know some of the possible causes of this, and how difficult it might be to repair.