Investigate the Woods of the Lost, northeast of the Greenstone Quarry.
Wood sprites are not prone to wandering, so I'm surprised they ventured down as far as the mason's quarter. Something must be forcing them out of their natural habitat.
These particular sprites are native to the Woods of the Lost, just north of here. I'd go myself, but I've heard those woods are haunted.
So yeah, that's out.
I guess we'll never know.
Orrrr... A big brave adventurer like YOU could go check it out! What do you say?