Right so this caught my attention because dogs fixating on a specific spot is genuinely one of the more reliable indicators that something's actually there rather than just a one-off noise. Animals don't sustain attention on nothing, that's the bit sceptics always struggle to explain away.
What kind of footsteps are we talking though? Rhythmic, like something pacing? Or more random, like something moving with purpose toward a specific point? Because those two patterns tend to suggest very different things in the literature on this stuff.
Also worth asking - have the dogs reacted to anything outside the house recently, or is it purely the ceiling they're locked onto? If its just the ceiling and nothing else, that's actually more interesting to me than if they're reacting to everything. Focused attention in animals usually means focused presence, if that makes sense.
Northumberland here and we get a lot of "roof animal" dismissals that frankly don't hold up once you dig into the specifics. What's the property like, old building?