Couldn't they just...
create a diversion like they've been doing this whole time when that kid Ethan broke in and was hiding behind the curtains so that he won't be found or to at least make a getaway? They could do all these "hauntings" and when they should have used them, they didn't?
W.W.V.K.F.R.G.D.? What Would Val Kilmer From Real Genius Do?