Yes. Many I should think.
Set a placeable treasure container in the toolkit down, and checks its scripts. NWN has its own treasure generation script. I think most mods don't use it, though, but its a good place to start an examination/understanding of treasure generation.
The easiest method, imo, is to start using NESS for your spawns. With NESS, you can just place some chests in a zone PCs can't get to, and fill them with loot. NESS has a good guide, easy to learn.
I used to use NESS, but decided to use my own custom loot generation scripts to have better control of the % chance that a given item will drop. I made my own loot tables. The actual script is pretty simple, but I have found, and suspect most would agree, that actually making the loot, the descriptions of the loot, and the loot tables in the script, is probably about 70% of the work that goes into a mod.
Anyway, the answer is yes. And I think a few are available on the Vault.