We found that we were getting water on the walls of cupboards that were along the outer walls. We now put dehunidifier units (chemical things with a bucket -- I forget the brand name) on the floor of the closets. i started by thinking there was a leak.
We had the mattress/sheets freeze to the back wall.
If you are getting water intrusion and you don't have the cabinets exposed to inside air, you might have a roof or leak along a seal. Check all sealant areas.