It's common practice in England to ring a telephone by signaling extra voltage
 across one side of the two-wire circuit and ground. When the subscriber
 answers the phone, it switches to the two-wire circuit for the conversation.
 This method allows two parties on the same line to be signaled without
 disturbing each other.
 
 An elderly lady with several pets called to say that her telephone failed to
 ring when her friends called; and that on the few occasions when it did ring
 her dog always barked first. The telephone repairman proceeded to the scene,
 curious to see this psychic dog.
 
 He climbed a nearby telephone pole, hooked in his test set, and dialed the
 subscriber's house. The phone didn't ring. He tried again. The dog barked
 loudly, followed by a ringing telephone.
 
 Climbing down from the pole, the telephone repairman found:
 
 a. A dog was tied to the telephone system's ground post via an iron chain and
    collar.
 
 b. The dog was receiving 90 volts of signaling current.
 
 c. After several such jolts, the dog would start barking and urinating on the
    ground.
 
 d. The wet ground completed the circuit and the phone would ring.
 
 Which shows you that some problems can be fixed by just pissing on them.