covid19 false positive tests?

Question

Why do COVID 19 antibody tests result in false positives? 

Answer 1

Same reason they come out with false negatives, as well as regular testing still has issue, we just don't talk about them anymore. As far as antibody testing, there are at least four related covid strains that are classed in with common colds, they travel among the population all the time. Just not nearly as server. There is also now a belief that Sars was actually much more wide spread then we thought at the time, many could still have antibodies from back then that are being picked up.