The line is wet as it goes out of sight above the tank.
That means it is leaking from above.....those are metal lines and they are part of the whole fuel sender......
To get to it, means dropping the tank, which opens up a whole other can of worms....you will have to move/drop the exhaust out of the way.....where the three lines come out of the tank and have a connection, those connectors might not want to come apart( might have to move down to the next connection).....if they do, then the next trouble spot is removing the rubber connector from the fuel fill line......then the next problem is getting the bolts out of the straps(they can be rusted or they snap the welded nut, and just spin).....then you lower the tank(it is always best to do this with less than 1/4 of a tank).......you either buy a whole sender, or you take a chance and cut out the leaking section and replace with hose that fits tightly over the remaining line and double clamp each end.....but to do this you have to drop the tank.....