It's never happened to me here, so already my post is worthless (I know this
)....BUT, in my old home this happened for years until I caught a city worker filling up vials from one of my outside faucets. He told me my home was a test home for the city water in my area. Since I had built that house, I knew the city never notified me, so I called them and gave them an earful. It wasn't so much the water...that was negligible, it was that they never informed me. I can't imagine TV doing this, tho. Also, contractors when working on the rental home next door would use my water, often assuming (usually correctly) that I was at work. When that house was ever empty and being worked on, I resorted to a little sign on the faucet reminding them that water was for MY home and if they had an emergency to knock and see me, if not, please don't use it.
Do you have your lawn serviced? They were required where I was to wash off the mower between lawns. Maybe that's it?