Signs of water damage in your walls can be light-brown or beige spots. You could also find a spot of peeling or flaking paint that's caused by excess moisture. These are clear signs of an active leak, and your first move should be to turn off the water to your home.
Signs of Water-Damaged Walls and Ceilings\n\n Peeling, flaking, or bubbling paint. Warped walls. Mold or mildew growth. Stains on the ceiling or walls.