I got a 2003 frigidaire, freezer on top style model # FRT18KG3CWO. Water is collecting at the back of this center fixture mounted at the top of the fridge, it houses the light, at the lowest part of this fixture towards the back of the unit water drips and accumulates only on the top shelf where we keep our tea and milk so we are constantly keeping a towel handy to dry the fridge. Im a auto tech and able to fix about anything, I just need to get pointed in the right direction.

Water is collecting at the back of this center fixture mounted at the top of the fridge

There is a small plastic tube attached to that fixture. This tube drains water to the bottom of the refrigerator where it evaporates.

That tube is blocked. Find a small flexible wire and run down the tube and clear it.

It sounds like you need to remove the cover over the freezer coils by removing the screws and sliding it out. It is on the bottom of the freezer. The drain is probably stopped up or it is not defrosting like it should. Take a look and make sure it drains. Make sure and clean the refrigerator coils under it as well by vacuuming and washing out coils. Use a water hose with spray nozzle to do this and keep water out of fan motor, but clean the blades. Replace all panels you remove exactly as you found them as they direct airflow. After you clean it out well let me know how it works. DrTom4444