I'm not an appliance guy--but I've had this problem before---pull out the drawers and look for the drain---clean that out and you will be fine---a vacuum cleaner might suck out whatever is clogging it---or a thin soft wire---
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you will have to remove the rear back panel of refrig section. You should then see your evap coil,under the coil is a drain trough and drain tube, most likely it is frozen over. Thaw it with a hair dryer and hot water.
................."I want a house that has gotten over all its troubles. I dont' want to spend the rest of life bringing up a young and inexperienced house"...........