Brett Favre's sister has been accused of destroying a
house ... by creating a gargantuan amount of dangerous meth fumes ...
this according to a new lawsuit.
Brett's younger sister Brandi Favre was arrested in a massive meth bust in Mississippi last year -- and now, a couple that lives next door to the alleged meth lab claims the fumes from the manufacturing process have wreaked havoc on their home.
According to the lawsuit, the couple claims a meth screening company detected "widespread meth contamination" in their home after Brandi's January 2011 arrest -- and recommended the entire place be cleaned.
As a result, the couple claims they had to find a new home for 5 months while their house was restored to a livable condition -- not only inconvenient ... but massively expensive.
The couple is now suing Brandi and her alleged accomplices for unspecified damages. Attempts to reach Brandi -- whose case is still pending before a grand jury -- were unsuccessful.
You've always got your family!
-TMZ