It's probably a small electric vacuum pump which should be under your dash or behind the front compartment door. It provides vacuum to your dash heater/ac controls. Most likely there is a leak in the vacuum lines from dry rot.
There are lots of excellent posts on this forum even with pics on how to chase it down and repair.
'07 Winnebago Journey 34H - CAT C7, Koni's, MCU's, SS Bell Crank, Safe-T-Plus
'07 HHR Toad, SMI AFO, Blue OX