Yes, guests can purchase a Guest of Honor badge that looks like a CM badge. This is what we did with our then five year old granddaughter. First of all, we had her personal information in a pliable plastic holder (baseball card thing) and pinned that inside her shorts. Just in case "we lost her". At our first park, I picked at a friendly Cast Member (the woman directing incoming guests at the Magic Kingdom. Then I showed Marlie how she could tell a Cast Member by their badge. That CM was great. She told Marlie that all Marlie needed to do was to find a person with that particular badge on it. It was a white badge. And not a red badge like some people wear. A white one and then the CM pointed out the slogan on the tag (this was two years ago so it's changed) and said that would be how Marlie knew. The look of relief on my daughter-in-law's face was priceless. We also did the "stay near the last place we saw you" thing. We've actually twice "rescued" lost boys and while they wanted to wander off, we kept them close to where they last saw their parents. Within minutes, they were reunited.
Then again, my 70 year old mother-in-law wandered away after a Braves game attended by 38,000 people and didn't do what she was supposed to do. Somehow, she made it to the car and was patiently waiting for us there. While we frantically searched inside the stadium for her. My father-in-law even got security involved. I thought my husband was going to explode when he was told she was at the car.