Help! How do I say this?

[twinkle]

A medium told me there is mold on the wooden floor board where the basement and first floor meet that has been making my family sick. Now, the mold cannot be cleaned since it is under the floor or the floor is covering over it. Everything else the medium said was verifiable and accurate. So, it is likely this is also true. However, my family does not believe in psychics/mediums. How do I hint there is mold? I already said that I read how mold is common in the floor boards of houses as old as ours, but the comment was ignored as if just something extra not to worry about.

I do not know if something can get rid of this mold without tearing up the floors, which my family would not do without proof there is mold.