 Somehow it's gotten loose, and it needs to be tightened. It's hard to tighten. You need what they call a strap wrench to tighten that. And when you tighten that up, it'll pull it back against the wall, and then you'll caulk it and seal it. It won't be leaking from getting behind the spout. It won't be leaking at the spout. You'll make it watertight, and you'll eliminate your water issue.