Huh.
wight (n.)
Old English wiht "living being, creature, person; something, anything," from Proto-Germanic *wihti- (source also of Old Saxon wiht "thing, demon," Dutch wicht "a little child," Old High German wiht "thing, creature, demon," German Wicht "creature, little child," Old Norse vettr "thing, creature," Swedish vätte "spirit of the earth, gnome" ...
Not related to the Isle of Wight, which is from Latin Vectis (c. 150), originally Celtic, possibly meaning "place of the division."
Was wondering how wight changed meaning from 'person' to 'immortal/undead being'.
Looks like the answer is, it always carried a couple meanings and now I'm curious why the English ignored the demon-y aspect for a while.