We don't use hair spray. The one thing that has changed lately (about a week ago) is that we are occasionally burning some ventless propane gas logs and we had some cabinets installed (about 5 weeks ago) in a library with a lacquer based paint. The pilot for the logs is burning continually. We have a propane tankless water heater. Our home was purchased new and is almost 1 year old now. Since we purchased the home I have noticed a faint mildew smell in the upstairs master bath where the sink top attaches to the base cabinets, but have never been able to determine where/why there is a smell there--nothing is visible to the eye. I am wondering if the smell is associated with a propane leak or possible mildew problem. Thank you very much for your help!