Gfci trips

There can be a few different reason for a trip. 1. Amps exceed rating off GFCI ie 15 amp receptacle can only handle up to 15 amp anymore and it will trip. 2. miss wiring; neutral must be on white screws hot on black and ground, green also inlet power (line) must be on bottom screws, outlet or load must be on top 3, a short, whether it be neutral or hot touching something in the box. Frayed wire, wire next to side of interior of box or yes moisture. Also a short in an appliance aven a new one can cause a trip. Remember if the refrigerator is on this same circuit, which is not a good idea it can cause a trip. At start up the fridge can spike to near 15 amps and a voltage spike can cause a gfci to trip. There are 20amp GFCI's so that can be your last resort, if all else fails.