Reason:

1, The thermostat should not be set on too high position. Operating constantly on strong position will cause too low temperature in the fridge storage compartment and ice may be formed there.
2, Frost or ice bead formed sometimes and melt other times on the back board of the fridge storage compartment It is mainly because the air in the fridge storage compartment is of high humidity. When the refrigerator is operating, the surface of the evaporator on the inner wall of the fridge storage compartment is of very low temperature and some moisture will condense on the back board of it and then freeze or frost. When the refrigerator stops operating, the temperature in the compartment will rise, and the ice bead or frost will melt  into water and flow out from the discharge outlet. So it is a normal phenomenon. In summer, as the air is of high temperature and humidity, this   phenomenon may become more apparent.
3, The water discharge outlet is blocked
4, Ice formed on the back wall

Solution:

• Set the thermostat at normal position
• To reduce the scale of this phenomenon, please pay attention to the following:
  (1)Try to reduce the number of times you open the door and the period of time it is opened for.
  (2)After a door of the refrigerator is closed, remember to check if it is closed tightly to avoid air flowing from the door gap.
  (3)Food should be stored with spaces between in the fridge storage compartment. In particular, please do not place food near the back wall.
  (4)Do not place food of high moisture in the fridge storage compartment. If you really need to do so, you'd better wrap it with a piece of preservative film (e.g. silver foil)
• Check if the water discharge outlet is blocked by dirt. If so, dredge it with a piece of hole dredging pin or similar plastic bar.
• call a service