The switch to the right of the FPR:
It was going drip, drip, drip. Apparently it's a common problem, but I couldn't find it my Ford service manual, couldn't find it on fordparts.com, and Car Quest couldn't find it either. So maybe this post will help help some poor bass turd, not unlike myself, in the future.
The Ford guy called it a "Vacuum Switch" part# E8TZ-9S283-A, $62.
I believe it's also called a "Restricted Fuel Filter Sensor." I saw somewhere it has an International part# 1809435C1 for $14.00. (I did not confirm that part# and that info was from 2005.)
The function of this leaky little bugger is to activate the check fuel filter light on the dash.