Billi, have you started any meds recently? It may not be a hallucination; lots of meds cause olfactory side effects; I had a heck of a time with some antibiotics and pain meds. When I came home from the hospital, my poor husband had to change the bed two or three times (and launder them) because the sheet smell was making me sick! There wasn't anything wrong with the sheets and washing them didn't help.