Sent home because they thought tylenol was a narcotic!?

Yep someone told my boss's boss that I had a narcotic laying on my desk. I was sent home because of it. But it wasnt a narcotic, it was Tylenol! Well now regardless I have to find another job, being accussed in this country is the same as being guilty. I was told to go take a drug test and come back if its negative. It will be..so what is my next move? How should I go about this? Or does anyone who works at the mercy of backstabbers trying to get your job?