Strange one...Interior light comes on when braking hardish

[largespiced]

My interior light will come on when I brake fairly hard, but nothing like an emergency stop. Any ideas? it will go out again after around 5 seconds!

 

[Edges]

Spring in the door pin switch I imagine to be getting week and the enertia of braking hard moves the switch to make the contact.. Just my first thought :/

im new to clios so sorry if I'm wrong in the way door switches work in these!

 

[largespiced]

This has turned out to be when the passenger seatbelt is tugged and forced into locking, say under heavy braking. Any ideas why or what needs fixing to stop it doing it?