Cause: Loose Screws
Over time, the pulling action applied to refrigerator door handles slowly causes the screws to work lose in their holes. The handles should be fully tightened when the appliance is delivered unless they were removed for protection in transit.
It usually takes at least a year before the handle screws begin to feel loose.
If the handle still feels loose after the screws are tightened, it's possible the handle or its mounts are damaged. Look for cracks or splits in the handle material where it attaches to the door.
The handle can be easily damaged if it is allowed to strike cabinets or walls when the refrigerator door is opened.
Solution: Tighten Screws
Using a screwdriver with the appropriate size and shape, turn the handle screws clockwise a few turns to keep the handle tight to the door. The screws are often located on top of the refrigerator door, or recessed inside the handle itself.
You may have to slide the handle or surrounding trim off the door if the screws are not visible.
Purchase a replacement handle from the manufacturer or your local parts dealer if the damage is severe enough to make the refrigerator awkward to use and tightening the screws fails to make a difference. Most major appliance manufacturers sell spares online through the company website.
See the Resource section for a collection of links.