Why is there water in bottom of my frigadaire refrigerator all the time?

My refrigarator keep water in the bottom. I set the settings in there. But I can not find where the water is coming from. My water tray under the Frig is always empty and dry. But inside it is holding water from somewhere.Please help me solve this problem. I have an Frigadaire Refrigarator,
manafactured; 12-99, Amps- 4.75, Volts-115, Hertz-60 I hope all this helps.