Component has markings "407J(M? symbol)41". It measures open circuit, has no significant capacitance. It is rectangular shaped and very thin, only 2-3mm.
It was used near a heated components. I guess it is a thermal switch, NO and closing at determined temperature. If the heater catches on fire, device will close, short out the supply, blow the fuse in a power supply and prevent power from reaching fire.
However, I could not confirm my guess after looking through thermal switch catalogues. Thermally operated switches usually use bimetallic strips which are much larger in size.
Any ideas?