On the post over here is mention of using a hybrid RAG + Fine-tune for customer service. The Medium article mentions the fine-tune improves tone and reduces hallucinations.
Here is the notional graph for the overall perspective on where this hybrid fits in:
The exact details in the article are thin, but I can envision how to implement this, and that it should be less prone to hallucinations and have the correct tone.
The fine-tuning is soaking up the patterns, while RAG is suppling the knowledge. The combo of the two, I would expect, is potent.