There is a lingering acrid sour somewhat pungent odor in my condo. And I have devellopped asthma because of it, unfortunately. Locating the source of the smell has been arduous. It's somewhat like amonia or a dead animal. I thought it might have been that my cat peed somewhere and it seeped through the carpet into the floorboards or something. First though, I got rid of all dirty laundry hampers, and tossed out wall to wall carpeting. Then I used an enzyme cleaner where I thought the floorboards may have been peed on. I also scrubbed with baking powder and vinegar. But the smell still remains. It's been 3 weeks since I vacated the premesis. Coming back daily only to feed my pet turtle. I can only stay in the condo for 1 minute at a time, with very bad lung irriatation, even wearing a heavy duty mask... After reading some threads in this forum I think I know what it might be, but not 100% sure. There is an ancient cieling fan above where I like to do my artwork. I had been using CFL lightbulbs in it, as I need strong lighting for my artwork. I noticed a lot of buzzing, and flickering coming from the bulbs. They would constantly go out as well, and come back on after switching sockets. I noticed the base of one of these was a bit burnt............. Now it's been 3 weeks of leaving all the windows open, ac fan on, air carbon/hepa filters going, and the smell is still here. Now, that light fixture may have intermittenly been in use while I stopped by to feed my turtle, but not every time, and not for long... What do you guys think? Could such a strong lingering odor really have come from one burning CFL? (I was only using one bulb at a time). And penetrate adjecent open concept rooms as well?..... Or could it be something else? ...Thanks for any advice!