Glow Mushrooms
A surprising number of fungi are bioluminescent: that is, glow in the dark - contributing to a phenomenon known as foxfire, from Japanese legends about fox spirits in the woods. You can see why these might seriously freak you out on a lonely journey home - I wonder how many ghosts/fairies/aliens were actually mushrooms? Spooklights seem to be a popular sighting in America: reminds me of the legends of will-o-the-wisp in England, which I think were actually due to marsh gases, and who lured travellers either into a quagmire or to buried treasure, depending on how lucky they were.
