I once had a strong smell that came up all of a sudden. It was like a sweet campfire and it was strong and wouldn't go away. I looked up causes and nothing fit. It was not a sinus infection or cancer (as one nurse suggested) and I was baffled. When I went to my dentist for my semi-annual cleaning I explained what was going on and she said it was a dead nerve and I needed a root canal. Often an infection can cause a smell rather than pain so I guess I was lucky. It was so strong and lasted so long that sometimes when I get stressed the smell comes back, temporarily.
@VictoriaNotes

My best idea of explaining it is that some way your sense of smell got confused. An ex wife and I were once talking at random when the smell of a sweet cigar was present in the room. We were home alone and both smoked at the time, but did not smoke cigars. Some people have told me it was a ghost present with us, but I doubt the ghost would be smoking. What likely happened was that our sense of smell got confused for a short time. We seem to recognize this with dogs but make up supernatural events when it involves humans.

Was it damp out?

If there are wood floors or paneling - old spills will come out if there is more moisture in the air. And smells will carry more of course if it's damp out.

This happened in an apartment my sister lived in at one time. Jean Nate whenever it rained. lol

My first thought after reading this was I remember my sense of smell functioning so much better after I quit smoking. Not trying to lecture just sharing my observation & experience.
I hope it's nothing serious as others suggest it could be. Please get checked out just to be safe.

Called the nurse hotline, just a freak of nature. No other symptoms of a stroke. Phew! You guys had me scared when you started talking about a stroke.

If you live in an apartment, it's entirely possible that a shared HVAC duct could have transferred a neighbor's air freshner through the vent.

If not, I'll concur with others who have suggested seeing a doctor.

I'm in agreement with consulting your doctor.

[mayoclinic.org]

Stroke

Stroke!