Update: I wired my contact sensors on the frame side for 6 years before a callback in Tulsa showed me why
Client kept getting false alarms every time her door swelled in humid weather because the magnet gap grew too big, and it hit me that mounting the contact on the door itself and the magnet on the frame keeps the gap tight no matter what the wood does, so I want to know if any of you still do it the old way on purpose.