Is there a way to bring a Specter back to life

He cannot cast the spell if the conditions for its casting aren't met.

This is distinct from him casting the spell and the spell failing, mind you. In order to cast the spell, he must be within the range specified by the spell, which in this case is touch. Now there is an exception to this in this spell, which applies if the body no longer exists. Given that the body is still in existence, I would say that the spell fails should he decide to try and cast it regardless but that the spell slot is not consumed. The reasoning behind this is that the range of the spell is part of its requirements for its casting, as much as any component, so casting True Resurrection without being in range would have the same result as casting it without a diamond: the process of casting it remains incomplete.

That said, if you are using the optional rule on Xanathar's Guide to Everything (p. 86), under "Invalid Spell Targets", the spell slot would be expended:

If you cast a spell on someone or something that can't be affected by the spell, nothing happens to that target, but if you used a spell slot to cast the spell, the slot is still expended.

That said, any high-level cleric would be aware of this, and would most likely not cast the spell.

You incur the penalty.

The wish spell has exactly one use that does not trigger the penalty:

to duplicate any other spell of 8th level or lower.

Any other use of wish triggers the penalty:

The stress of casting this spell to produce any effect other than duplicating another spell weakens you.

Replicating a spell is not good enough for disintegrate.

True resurrection can get the job done for reversing disintegrate, but as a 9th level spell, it is not eligible for duplication via wish. For 8th level and lower resurrection spells, the trouble is that once you replicate a spell, you are not casting wish for the purposes of resurrection, you are casting the spell. Wish says:

The spell simply takes effect.

Casting one of the lesser resurrection spells with wish does not count as using wish for resurrection; all wish does is produce the effect of a spell that is not powerful enough to reverse death-by-disintegrate.

To use wish for the purpose of reversing a death-by-disintegrate, you must wish that creature back to life, and trigger the penalty.

Finally, as RevenantBacon observed in a comment, the spell true resurrection would be totally pointless if wish could replace it without penalty.