Frost Free, here in the Colonies means a fridge that has a heating device behind the back wall that turns on and off when prompted by a sensor. When it's in the off position, frost from excess moisture in the fridge collects on a metal plate (of sorts) and when sensed it turns on, heating the ice and frost which melts and drips down to the drainhole you describe.
Most likely the device has failed... either entirely or at least the heating unit. This can be replaced with a medium amount of difficluty... since the back plate of the freezer has to be removed and the unit accessed for replacement. My best guess dependent on experience...