Water leaking inside the refrigerator can usually be caused by an open container or could be coming from the water filter.
If a food container was placed in the refrigerator and was not completely sealed or came open somehow, the liquid in the container could have leaked. Check all containers and reseal them securely. Clean up the spill with a warm, wet cloth. Dry everything thoroughly afterwards.
If your refrigerator has an icemaker on the refrigerator door, make certain that the door to the icemaker compartment is shut all the way or the air will escape which can prevent the compartment from maintaining the proper temperature and, as a result, the ice will melt and leak into the refrigerator.
Make certain that the water filter is inserted properly. Check the O-Rings at the end of the filter to see if they are stretched, cracked, or seated incorrectly. Check the filter compartment for cracks or damage.
It is normal for some moisture to condense on the walls of the refrigerator when the doors are opened or closed. This will happen more often during the warmer, more humid months. Wipe up excess moisture with a dry cloth. Check the seals on the doors to make sure that they are not dirty or torn and thus preventing a proper seal.