I had used one of the thermal cameras from work to view inside the walls of my parents home before it was sold.
I wanted to make sure that my dad didn't wall up any treasures before the house changed hands.
Didn't find any treasure.
What the camera did do though was outline the framing in the house! On a very cold day I could see every piece of lumber that drywall was mounted to and the lack of insulation in some areas.