I guess mine is with a lighted button. Not sure. Got to go home and check.

Is the voltage only sent when i press the button? I believe the line always has voltage. As i tried the electric/magnetic sensor and it always detects the current.

I also see another post about doorbell trigger. Looks like i might be able to achieve this by ELK-930. Need to check on how to install the ELK-930.

[Link: remotecentral.com]

May be what i write does not make sense because i have no clue about voltage sensors and how voltage works.