Find leak at cleanout. Upon arrival customer has residue on wall from what would look like a leak. Around that area there is a cleanout plug that was not inserted into the wall. It appears that because that plug was not seated that water was getting through. I gave option to clean and dope and reseat the plug for the minimum plumbing charge or we could open the wall to be absolutely sure that was the only problem. Customer would like to just to do the minimum plumbing charge for now. Took payment and emailed customer.