There's a Ghost savage progression - but it might not meet your needs.
If your goal is to bring this character back as a Ghost without making them eat the +5 LA immediately, you can use the Ghost savage progression template class, which lets them gradually gain the features of the Ghost template over several levels.
You're not required to take all the levels of this class - you can take the first level of Ghost and then go back to leveling as normal, missing out on most of the template's features. This is clarified in the general rules for template classes:
Characters are not required to complete all the levels of a given template class in uninterrupted succession. For example, a character who takes a level of wereboar could then take a level of fighter and a level of rogue (or any other combination of other class levels) before taking another level of wereboar. A character must still take the first level of wereboar before taking the second, just as with a normal class.
However, this might not be a good idea. Being incorporeal is in some ways a huge advantage - it makes you really hard to harm - but for a character whose classes are Rogue and Paladin (i.e., not spellcasting classes), it's also an enormous drawback. How are you supposed to contribute to the party if you can't use any of your normal methods of attack?
Here are a few other possibilities you might consider:
- Have a necromancer bring them back as some other form of undead that doesn't hamper their abilities so much. There are too many possibilities to list them all here, but the sourcebook Libris Mortis has lots of great template options for this. Plus, "break free of the necromancer's control" or "become a living thing again" is a great character arc, if your player is into it. If your player isn't into it, though, don't force this on them.
- Reincarnate them, and just fudge the results if you have to. Not "give them whatever form they want" fudge, but "reroll if they get something that completely ruins their character and makes the game unfun" fudge.
- Bring them back with DM fiat, with some sort of cost associated with it. Are they on a Mission From God? Then have that God bring them back, but give it a cost - they inherit some kind of divine curse, or have to do [something something character sidequest] to pay off their debt, or something.
Fortunately, since you're the DM, you have lots of options.