need help finding interior light cover.

[CrawlingEye]

I know you're probably going to say "toyota dealer or junk yard" but I already tried a toyota dealer, and I'm not so sure of a junk yard.

I need the interior light cover, the little red one that goes on when the door is ajar. My car's a '93 camry, and it's the passenger side cover (right under the arm rest).
The dealership made it seem like it was nonreplaceable.
I'm wondering if it's nonreplaceable, then how the hell did it snap out? It clearly didn't break (there's little hooks where it would've gone).

Thanks all.