My air conditioning smells like someone is smoking or dirty ashtray I'm scared is this smell normal?

How long ago did this smell start?

Ijust noticed today

It could be the Dirty Sock Syndrome. The interior A/C coil probably has bacteria or other odor causing debris attached to it causing the problem.

What is the “Dirty Sock Syndrome?” (http://www.foxservice.com/kb/article-8.html)

Dirty Sock Syndrome (http://powervacamerica.com/Newsletter/vol4issue4/vol4issue4_article2.htm)

OR go here for more searches

dirty sock syndrome - Google Search (http://www.google.com/search?hl=en&q=dirty+sock+syndrome&aq=f&oq=&aqi=g3)

Is there any chance that your AC is pulling outside air into the home from a place where someone is smoking? My wife swears she can smell me smoke a cigar outside with all windows closed.