If there is mold growing on the dirt and moss, then you probably have the humidity too high in the area that you are growing your Venus fly traps and they are probably being kept too wet. Contrary to what most people believe, Venus fly traps don’t require high levels of humidity nor do they like to have their soil soaking wet. I live where the humidity is quite low during the summer (30% or lower), and I grow all of my plants outside and they thrive. So, first off, I would recommend lowering the humidity that you have the plant growing in. Secondly, I would recommend not keeping the soil too wet, but rather just moist. To get rid of the mold, I would simply repot the plant. If you need to learn how to repot a Venus flytrap When you repot the plant, make sure to inspect the rhizome (the white bulb part of the plant) to make sure none of the mold has spread to it. If it has, I would cut off any infected part.