I have a unique application for a residence. When the Garage doors are open, we want a CO line button to flash (as if an incoming call). My thought was to wire a simple switch that would pass ringing voltage (from a WE power supply unit) to a CO line jack (408 card), then assign that to the stations wanting the signal. My questions are would this damage the CO port (ringing voltage could be constant for hours when the garage door was open), or would any damage result from someone picking up that "ringing" line since the ringing voltage would never stop since the garage door was open? The CO line preference would be programmed not to automatically select and No ring. Previously when an 1A2 system was in place, the same solution worked.