This is one sneaky dude or something. I cut I hole into the drywall to be met with more drywall to find that a return vent made the whole area accessible ... (fml) ... he wasn’t in there. It also happens to be the laundry room so I took all of the covers off the washer and dryer and no dice. The flour line hasn’t been messed with other then the area I know he is coming in and out from.
Back to the drawing board and left a hide and water out next to the area.