The last 2 nights we have been awakened at 4-5 am by an extremely high pitched noise (not a beeping, but steady)-the first night it was followed by our alarm sounding and the display pad reading check family room windows. There was no breach in security, the system reset without problem and the noise stopped. Last night I was once again wakened by an ear splitting noise but ran for the alarm panel and shut it off before the alarm could sound (so as not to wake the children). Once again the sound stopped as soon as the system was shut off and this time there was no trouble message. Our alarm company is at a loss and insists the alarm doesn't make such a sound. Has anyone ever heard of this before?

Thanks for all these useful points. Can anyone share how to find a local monitoring company for those who want to do the install themselves? Also, I'm interested in having a cellular system (we don't have a land-line). Any ideas on if this is less common than land-line monitoring? ADT tells me the cell system doesn't use existing cell towers and that they have their own networks, is this accurate?