Ghosts weren't scientific and couldn't be weighed or quantified, but neither could the Triforce, or any of the spells the other Champions had mastered, so that didn't rule the possibility out. Especially not in the mind of someone who didn't think like a scientist unless it was strictly necessary.
"There is a chimney," he said, a bit slowly, and pointed straight back where the empty weapon mounts were. "Right back there, next to the washroom."
Then he pointed to the wall on the left, not turning to do so, though he sorta turned his head in her general direction, not moving his eyes from that wall-that-shouldn't-be-there to actually look at her. "And the house extends out on that side."