4 Answers

As Felix said to Oscar, "CHECK THE TRAY UNDERNEATH THE REFRIGERATOR!"

It is more than likely the tube of condensate coming from the frost free part of the freezer, to the evaporator pan at base of unit.  You see, the condensate (water) comes down and usually enters the tray, or pan, via a tube and a hole in the pan, allowing it to enter tray from tube.  Well, dust and debris can clog this opening and then the tube leaks as it cannot get into the tray, so it will go on floor.  You can take off the front grill, and vacuum the tray, and cooling fins while there.  then, if you can see the tube, remove it from the tray, and blow into it, or ream it with a wire to unclog the gunk in it.  This should end the problem.  Usually that is all that it is...

It could also be a water line going in for making ice,  and the line might be broken, ext.