You cannot test positive on the basis of secondhand smoke.

I have read that a faint line is still a pass but its so faint, could this be because of the second hand smoke from last night? I've ordered some more tests hopefully it was from the second hand smoke but I am doubting it could affect a urine test
There is no meaning attributed to the intensity of a line. Even synthetic urine controls (which contain no drug metabolites at all) can register a faint line on an assay.

Its still a negative. A negative is a negative.