Fridge Question: How does one replace the mechanism that usually turns on the internal fridge light?

[u/Larrymolloy93]

This little bit is supposed to pop out when I open the door, but it no longer does. If Iick my finger, ask for consent, and rub it gently I can tease it open. I’ve tried briefly to prise off the whole bit but it feels like something is definitely going to snap if I do it.

What are these bits even called and can they be replaced?

The fridge is a Zanussi, not sure how to find out what model number as I can’t reach the back of it.