Windshield Wiper Fluid warning light

What is your question?

About two months ago a warning light came on my dash that I had low or no wiper fluid left. So I bought a huge bottle of it and filled up the tank. The next day the light was on again, I put it more. The Light has been on ever since and I have no wiper fluid in the tank anymore and I'm not about to fill it up again. A leak or a bad sensor or what? Thanks RS