Kitchenaid side by side refrigerator Model # KSCS25INBL02

We bought this unit brand new back in 2006-07. Overall, it has been a pretty reliable unit except for one particular issue. For probably 10 years or more, there has been water that leaks from the freezer compartment once a day. It produces a large puddle of water that is a safety hazard when you walk through the kitchen on a tile floor. It is quite slippery. I have taken off the back panel inside the freezer compartment to try and locate a frozen/ clogged drain line but did not find anything. I have pulled off the back panel on the rear of the fridge to see if the unit had one of the faulty "duck bill" check valve and it doesn't. It already has one of the "P-trap" style tubes. That is the extent of my troubleshooting abilities.