Found this Tripod with a container (probably propane) hanging from it and a red tube connected to a batterie ontop. It was near a hunting perch in the Black Forest, Germany.
Found in the middle of a disc golf course in Colorado. Seems like a glass jar with tubing and a toothbrush taped to it, nothing in the jar that I could tell
This is under a seemingly random cabinet in the kitchen. It's plastic and looks like a tiny vent but doesn't seem to be connected to the HVAC. It seems to open and close with the button/rocker on the right.