Dash Lights Incorrect
 

I'm thinking of buying this F250 from a dealer, but he said the instrument cluster needs to be replaced. A couple of the dash lights are on (doors open, check engine, check gauge, etc.), and he said that's why it needs to be replaced. The cab lights are also unreliable, sometimes they turn on when I open the door, sometimes they stay on after I've been out of the truck for 20 minutes. So, I'm wondering if replacing the instrument cluster would fix this, or if it could be a bigger issue?

Also, if it's just the instrument cluster that needs replacing, where can I find one I can install myself? The truck is a 2002 F250 diesel with a 7.3L Powerstroke engine.

Thanks!