Fungus of some kind - indoors?

Fungus of some kind - indoors?

Observation - Fungus of some kind - indoors? - UK and Ireland. Description: I cannot imagine what these are - can anyone help? They appeared on the painted wooden window frame in an unused and unheated room (indoors). Two little round lumps approx 1cm across which when knocked off we found were actually a thin papery whitish oute

I cannot imagine what these are - can anyone help? They appeared on the painted wooden window frame in an unused and unheated room (indoors). Two little round lumps approx 1cm across which when knocked off we found were actually a thin papery whitish outer casing enclosing a fine brown powder. The powder was hyrophobic and hard to wipe up. No obvious sign of dampness or rot on window frame.