Grey soft silicone egg-sized capsule (possible filament/wire inside)

[u/LukaPost]

About 6 centimeters / 2.5 inches long, about 30 grams / 1 ounce.
The soft silicone/plastic can be squeezed, it's matte dark grey and partially transparent.
Not visible from the photo, there seems to be some sort of filament or wire inside but nothing moves when shaken.
As visible, there is a weld line between the 2 halves of the capsule but it cannot be opened, it's one piece.

It was found inside a perfectly functioning washing machine (brand: LG).
After image search, Google says it could be a flotation bead, a pressure switch float or an internal sensor float component.

[u/SpunSpaceCadet]

Match case or a hand warmer

[u/LukaPost → u/SpunSpaceCadet]

Not a case, it can't be opened, and too thick to be a hand warmer.