Water on Refrigerator door

There is a little water underneath the bottom shelf of the refrigerator (inside the fridge) and a little ice underneath the bottom shelf of the freezer. I wipe it everyday and the next day it is there again. Could it be condensation? Are there heaters to prevent this that are not working and I could replace? The Power Saver switch is ON so I guess the heaters are ON. Thanks in advance for your help.