The house I inspected yesterday gave off high readings on the moisture meter on most of the walls, including inside walls. The walls appear to be some kind of plaster coating over drywall. I used the drywall setting and the meter went wild. If I used the plaster setting, the reading was normal. There was no evidence of leaks anywhere, including the roof, plumbing, or around windows. No moisture stains on ceilings or walls, no rust or mold in window sills, etc. I'm not sure how to report this. Any suggestions?