The Spirit and the Mouse

In the Western Residence, which is where the last part of the story takes place, there is an old Kibblin box that's rusted and covered in leaves in a corner. That's the easiest to reach for this achievement and you can net another the "Out of service" achievement there too.

To reach the top, simply climb the only staircase in the area. About halfway through the second set of stairs, stick to the right and there will be a hole in the railing, you can climb down to the beam below and make your way to a lightbulb, then drop down to the top of the out of service Kibblin box.
Once there, wait without moving or leaving the game for a few seconds for the mouse to lie down and you will be netting the two achievements.