I looked and there is no mention of The Fade that I could find. But the homebrew it likely comes from resembles the Shadowfell.
The Shadowfell, sometimes simply called Shadow, was a parallel plane from which necrotic energies and shadow magic stemmed. It existed as sort of a counterpart to the Feywild in the sense that it was a reflection or "echo" of the Prime Material Plane except that it was a bleak, desolate place full of decay and death.
The Shadowfell was created in 1385 DR when Shar, having successfully arranged Mystra's death, bound the energies of the Negative Energy Plane with the Plane of Shadow.
Much of the Shadowfell was a twisted reflection of the Prime Material plane and was populated primarily by dead creatures such as ghosts, specters, and other undead who for whatever reason refused to leave the Shadowfell and continue on to the Fugue Plane. There were however, numerous other inhabitants, such as communities of shadar-kai, Shadovar, and dark ones.
↑ 2.0 2.1 2.2 Bruce R. Cordell, Ed Greenwood, Chris Sims (August 2008). Forgotten Realms Campaign Guide. (Wizards of the Coast), p. 69. ISBN 978-0-7869-4924-3.