A ghost-wipe is being lucky enough to squeeze out a clean poop that leaves no trace behind, thus no need for wiping. The perfect crime. However, this phenomenon occurs about as often as the McRib comes around. For all normal poops you have to make the decision on when to stop wiping based on how you feel, and what the toilet paper is telling you. These really are the only two ways to determine when to stop, so it is safe to assume that blind people have a higher percentage of skid marks in their underwear. One proven, although rough method is the traffic light method. This was sent in and illustrated below by a No. 2 guide users. Enjoy!