A quality bar of handmade soap will often "sweat" in humid weather due to the high content of natural humectants. A humectant is a substance that readily absorbs moisture from its surroundings and handmade soap is high in glycerin. The sweating is actually moisture from the air that the glycerin attracts. There is nothing wrong with your handmade soap and is safe to use. The wetness is just the glycerin and other natural humectants doing their job.