It could be... A sudden phantom smell of smoke (when no smoke is present) is called phantosmia. MS can cause phantosmia, not too common but there is. I smell smoke sometimes, always check everything in the house to make sure...

Ohh your definitely not alone in that. Since I suffered with Bell's Palsy in 2011, that is a major thing. Hearing extreme ppl in the office thought they were whispering and I hear them - was funny at times, smell extreme (to the point of being allergic to air Bourne citrus (peeling in my presence not consuming an absolute nightmare)I smell things noone else does from good food, bbq,burning, grease,just random and taste not so good. whilst Bells should have been temporary its connected with MS now too.