Really odd water issue

So we are staying in Northern IL, and last night got a huge storm rolling through overnight. Personally, it was the worst one I've ever been in while camping, I was sure there was going to be damage. I was up all hours checking things and making sure water wasn't getting in and whatnot. One time I woke up and my pillow was wet. It's very odd because there are no seams or places for water to come in. Our master bedroom is the front of the camper. I am taller so I tend to sleep with my head pretty much right against the front wall, which is the leading edge of the camper. The wall was damp to the touch, but I could not identify any 'running' water or trail. My pillow was wet and the parts of the sheet that touch it were also. Nothing else was wet - nothing on the floor, walls. . .. like I said, absolutely no place for water to get in that particular spot and nowhere else. We tend to keep it cool (like 70 degrees) at night. All I can figure is maybe condensation from being so close to an outer wall? It has been ungodly humid and hot.