I just replaced my swithes in my hall, both switches at the end of my hall turned the lights both on and off. Now 1 switch must be on for the other switch to turn the light on & off. What happened. I thought the wires were put back on the same screws.
IMPORTANT when replacing 3 way switches. different manufactures have the common screw in different locations. So, when replacing, it is necessary to identify the common wire on the old switch and place it on the common of the new switch