Ford considered the question, putting himself in the Muggles' shoes for a minute. If his livelihood was scaring people who stayed overnight, he would want the furniture moving to be loud enough that it couldn't help but wake them up, and close enough to where he expected them to be that they could see it, when they went to investigate. That was the whole point of the wires, was that they were hard to see — unless you knew where to look for them, the furniture could move right in front of your eyes and you wouldn't know how it was happening. Of course, Ford had approached this with the same sort of candid curiosity as Lestrange had, when he'd first seen it. He was less interested in how it was moving than in how Muggles were moving it, which had allowed him to learn how to spot the wires quicker than the typical skeptic.

"I think they'll do it in one of the rooms next to the ones they told us to sleep in," he speculated. "Or right above us. Something loud enough to wake us up, if we were asleep. And then something in the hallway, in case we were brave enough to go look."