Some people in Iceland, and in other countries too, see elves for example in elf-cliffs and in Nature. Light-waves, or some invisible waves, have been detected by fine instruments. So this superstition is supported by measurements.
Elves could be elvur, i.e. rivers and channels, in Sanskrit shrota, in our physical body, meant for the fine flow of nutrients to all organs.
Álfar, elves, are delicate power in our ancient myths. We love them and adore them and want to have them and know them.