Gibson design has water under the crispers

I have a Gibson Refrigerator, Model #RT17F6WN. I am assuming it is around 15 years old. The refrigerator and freezer work well (the food is kept cold). The problem is that every day for about the last month there is water inside the refrigerator compartment and sometimes on the floor. I have not seen the water inside the freezer compartment. The water is found on all three shelves and it also collects under the crisper drawer. I have seen water dripping from the door-activated light switch and I have seen water dripping from the air ducts (??? I am not sure what these are - there are two holes molded into a plastic piece that is mounted on the top of the refrigerator compartment towards the back and the ducts look like they connect to the freezer compartment.) Therefore, I assuming the water is coming from the freezer when it defrosts. The tray underneath the refrigerator is empty. Can you help me out with this problem? Thank you,