The old wives' tale advises that if the shingles rash meets around your middle, you will die, and maybe this is where the notion comes from. As someone who has had shingles, I can confirm that if that does happen, the sufferer would probably prefer to die! Shingles is a really painful infection, it inflames the nerve under the skin, but as a relative of the chickenpox virus, it is not usually fatal.
Not a relative, andy. Shingles is a reactivation of the same chickenpox you had as a kid. If on steroids or an AIDS patient, it's possible to get generalised shingles which can most certainly kill you. Fortunately very rare.