I talked with a customer today that had worked at another Patel Motel,he said they had a device on the door which would ring his cordless phone when the door opened ,ever Hear of one ,if so what brand and info ,If I were guessing i would say it was a two mline cordles and some stand-a-lone device was hooked to second line or it interfaced with an alarm system.the way he vaguely described it it was a completely different tone. Thanks