Well, if you are smelling gas and others are smelling gas, it is likely that your gas detector is smelling gas too. You need to figure out where the gas smell is coming from and get it fixed.
That said, the gas detectors can be set off by other things.
Each year when I pour RV antifreeze in my p traps, my gas detector goes off. I know it is NOT propane or CO, because neither my furnace or my propane is turned on, and it isn't low battery because I'm plugged into shore power. I open the door and turn on the bathroom fan, and after about 5 minutes the alarm stops. I keep ventilating and the alarm stays silent even after I shut the doors and windows. This has happened for 3 consecutive years (as many times as I have winterized). My alarm clearly does not like RV antifreeze.
