A cable repairman was checking a new digital phone system in an old historic home. The home had been switched over to cable telephone the previous month. But the phone line had started going completely dead, mysteriously fixing itself just minutes before the repair man arrived.         

As the repair man was about to leave the home owner alerted him that the phone had suddenly gone dead again. He disconnected the main phone line and was able to get the dial tone from the street line.

When the house phone was reconnected it was once again working. The repair man thought the problem could be a line short but the temporary disconnect fixed the problem. 

After checking all of the house phones one line was weaker and had some static. Picking up the kitchen phone the repair man heard the unmistakable beep, beep, beep of someone dialing. But no one in the house was on the phone.

What was causing the phone to go dead intermittently? What was the dialing sound that the repair man heard?

The Rest Of The Story

The security alarm console in the kitchen was connected to a controller in the basement. Guess what was connected to the alarm control? A phone line, of course.

The alarm computer was not too happy when someone disconnected the power to the console in the kitchen and called headquarters. 

When headquarters' main computer checked the active customer log and found that no one was paying the bill. The master computer simply hung up.

The result was an open line every time the home security computer waited on the line for the master to reply.