My bedroom has developed a disgusting smell. We've tried to find the source but can't. The bedroom is a converted basement. We've lived here for over a year now and about a fortnight ago, a disgusting smell appeared from nowhere. We initially thought it was down to our cat!!! We've searched the whole room and found nothing. It is really difficult to pintpoint exactly where it is coming from, however, it appears to be coming from the ceiling. We've looked upstairs at the floor and can't find anything there either. I write in desparation for some advice on how to trace this.