What Causes False Positive Results For Alcohol In A Blood Test?

Hi! I have been sober 13 yrs. today. I have two spine fusions so I have to do random UA s since I m on a contract for opioids. I tested positive for alcohol. I was shocked since I know I didn t drink. I m sureness everyone here s that story, but in my case it s true. We did a confirmation test to check the levels of alcohol. It s negative since there was a trace amount. I have diabetes in my family. My question is I d like to find out why this happened. What s the best specialist to see? Thank you! Karen