Lyme disease can cause olfactory [smell] hallucinations -- I have had them. The ENT (ear/nose/throat) MD I saw didn't know what it was, but my Lyme dr did. They come and go.
However, if you don't have any of the other signs or symptoms of Lyme, then I would think the likelihood that you have Lyme is low. However, I'm not a doctor, so can't say for sure.