"apparition of a living person, specter, a double," 1787, an English dialect word of unknown origin (see OED for discussion).
A peculiarly weird type of apparition is the wraith (q.v.) or double, of which the Irish fetch is a variant. The wraith is an exact facsimile of a living person, who may himself see it. Goethe, Shelley, and other famous men are said to have seen their own wraiths. The fetch makes its appearance shortly before the death of the person it represents, either to himself or his friends, or both. [Lewis Spence, "An Encyclopedia of Occultism," 1920]
Old English wrað "angry" (literally "tormented, twisted"), from Proto-Germanic *wraith- (source also of Old Frisian wreth "evil," Old Saxon wred, Middle Dutch wret, Dutch wreed "cruel," Old High German reid, Old Norse reiðr "angry, offended"), from *wreit-, from PIE root *wer- (2) "to turn, bend." Rare or obsolete from early 16c. to mid-19c., but somewhat revived since, especially in dignified writing, or this:
Secretary: "The Dean is furious. He's waxing wroth."
Quincy Adams Wagstaf [Groucho]: "Is Roth out there too? Tell Roth to wax the Dean for a while."
["Horse Feathers," 1932]