? maggot inside casing

? maggot inside casing

Observation - ? maggot inside casing - UK and Ireland. Description: Casing 1cm long. Appears to be a small 'maggot' inside strange casing. Maggot never fully emerges, but pulls casing behind it when moving. Possibly spins thread. Found hanging from bedroom ceiling. Can anyone identify this?

Casing 1cm long. Appears to be a small 'maggot' inside strange casing. Maggot never fully emerges, but pulls casing behind it when moving. Possibly spins thread.

Found hanging from bedroom ceiling.

Can anyone identify this?