Our house was build in the 1910's and our bathroom is located between the two bedrooms and shares the wall to the outside. Over the weekend we started to smell a foul broclii like smell coming from the bathroom. So we took a piece of the wall apart which is were we thought it was coming from and there wasn't anything there, then we took the toilet apart and still nothing. We haven't tried our atic but we know that it isn't coming from the crawler because we checked it out.The smell is only in the bathroom and no were else in the house. We do have natural gas in our house but that also isn't were it is coming from. Please help us we don't know what to do??