There is no reason to have to take your wallet out before you go through the WTMD unless it contains metal. If that's the case, either take the metal out and keep the wallet or place the wallet inside your bag or jacket. Never leave it in plain view. If your wallet does alarm the WTMD and/or HHMD, the SOP says it HAS to be x-rayed. When I'm wanding someone and thier wallet alarms, I always hand them thier paper money before I x-ray the wallet. I don't think that's SOP, but a supervisor suggested we do that to help cover our behinds in case someone accusses us of stealing. FWIW, I always keep my wallet in my pocket when I go through the WTMD when both working and traveling. I keep a spare car key in there and it has never alarmed a WTMD anywhere.