Hearing things is a paper note in Fallout 76, introduced in the Expeditions: The Pitt update.
Location[]
The note can be found on a barrel in The Sanctum's sewer section in The Pitt, during From Ashes to Fire. It is in the room with the large Tesla arc trap.
Transcript[]
Think I'm losing it down here.
Maybe it's just my imagination but I could have sworn I heard one of those little bastards say my name.
That can't be, they're just god damn monsters.
Now that I think about it, it did kind of look like my old bunkmate. Fucked up face and everything.