It used to be common practice in England to ring a telephone by sending higher voltage across one side of the two wire circuit and ground ("earth" in England). When the subscriber answered the phone, it switched to the two-wire circuit for the conversation.
This method allowed two parties on the same line to be
signaled without disturbing each other. An elderly lady called
the phone company complaining that her telephone failed to ring
when her friends called; and that on a few occasions when it did
ring, her dog barked first. The telephone repairman proceeded to
the scene, curious
to see this psychic dog.
He climbed th nearby telephone pole, hooked up 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 that:
a. There was a bad connection on the telephone grounding post connecting the house to ground.
b. The dog was tied to the grounding post via a metal chain attached to a metal collar;
c. The dog was receiving 90 volts of signaling current through his neck to the damp English ground, just enough to shock the dog but not enough to complete the circuit to the phone;
d. After several such jolts, the dog would start barking and urinate on the ground;
e. The now-soaked ground helped complete the circuit if the dog stepped in it, making the phone ring.
Which shows that some problems can be fixed just by pissing on them --if only temporarily!