Metho in fuel?

[RWD4ever]

Is the above true? Doesn't ethanol attract moisture? How long does it take for it to actually produce a worrying amount?

I remember one of Jack Absolom's TV shows, where he suggested if you filled up your car at some lonely one-horse town, you should chuck a bottle of metho in the tank, because the alcohol would mix with water, which might be already in the petrol.