So: someone you know has Seen or Heard Someone.
We have it from the ancestors that these things do indeed happen from time to time. Maybe they've happened to you. (I've had my share of visionary experiences over the years.) When it comes to trustworthiness, though, we're clearly talking case-by-case basis. How do you tell the real from the...um, not-real?
Forthwith, some pointers to help guide the way along the thorny path of personal revelation.