On second thought, minniemoo, with a possible ray of light… if your fridge is a fridge and freezer combo, there's a fan that moves the air from the freezer to the fridge through a small, electronically controlled opening between the two compartments. It is possible that that fan is failing… either the motor or the fan blades themselves. This is rather inexpensive to repair… Hope!
If this is the type of unit you have, turn down the temperature control so as to demand colder air, hold the door switch closed (on the door that turns the light off when the dodo's closed), and listen to the fan and feel the air moving… see if there's any strange sounds or no air moving. If this was the cause, the fridge would be getting warmer, even with the unit running...