Nocturne has three cards that tell a player to "exchange" a card for another card. The card being exchanged is returned to its Supply pile, or non-Supply pile...
—The Rulebook of Dominion: Nocturne, p. 4 about “exchange”.
When you play a Rogue to gain like a Silver (a Ghost) from the Trash triggering the when-gain effect of Changeling, if want you return it to its Supply (non-Supply) pile for a Changeling, clearly right?
How about playing a Rogue to gain Zombies from the Trash? I guess they are similar to Shelters and Heirlooms as far as they don’t have specific “piles” they come from so that you can’t exchange them to Changeling, as is implemented online. One relevant thing, however, is that the Trash is sometimes referred to as “the Trash pile” in Rulebooks, such as of Dominion, 2nd edn., p. 8, 9, and 11. Is the Trash the “pile” Zombies come from? Is “the Trash pile” just descriptive of the Trash, not a specific term?