fridge leaking inside but not from drain tube

Over the past cople of months my fridge has been leaking water on the interior. I have monitored it closely for the past couple of weeks. It is leaking in the back from where the air from the freezer enters the back ceiling of the fridge. I have taken the following steps with negative results to fix it.

  1. unplugged for four hours to defrost.
  2. taken apart the back wall to the freezer and fan cover to inspect the drain areas, where no obstruction was detected.
  3. Taken apart the assembley on the ceiling of the fridge with nothing unusual detected.
  4. Checked and cleared the drain tube by flushing it out, with no obstruction observed.
  5. Checked the fridge and freezer door gaskets for craks or leaks with nothing unusual detected.

As far as I can tell during each defrost cycle, the water is randomly dripping from the area of the freezer fan air into the assembly on the fridge ceiling where the freezer air enters the fridge, more specifically, into the four square holes in the styrofoam damper on the fridge ceiling assembly.

Any ideas or solutions is greatly appriciated. Thanks in advance for the help.

Dan