Yesterday after returning from helping others gut homes, I went to the fridge for a glass of water, and the refrigerator was on, but it wasn't cooling. I am no repair person, but I think it's time for a new refrigerator (this one came with the home)
Were there any particular circumstances leading up to the not-cold fridge? Kid left the door open over night? Freezer door looked closed but wasn't?
Check for ice way in the back. There's usually (sometimes?) a fan that circulates the cold air from freezer to fridge. Humidity from an open door can lead to ice freezing up that fan and possibly cause that motor to burn out. Sometimes I can defrost the fan and/or the coils with a hair dryer, but other times I've gone to an appliance store and bought the $35-40 part. Faster and cheaper than waiting for a service call and it will keep an otherwise good appliance out of the landfill.
Google your model number. Good luck. And if you have young children, be careful with the pullout freezer on the bottom models. You'll become an expert on re-aligning the jumped tracks when that door doesn't close.