Dome light is the interior light, yeah?
I've never looked at mine but:
Try the door open buttons and clean the contacts.
If the on/off switch is integral to the light, the switch mechanism is likely broken or bent.
If switch is on dash you could well have a leak to earth (Interior light switches break the -ve side of the circuit usually)between the -ve pole of the bulb and the switch.
There's not a lot else it can be!
Phil
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