The fridge does a defrost cycle one per 24hrs so that frost and ice don't build up on the cooling fins. Your leak is likely occurring during this event, and somehow the water isn't draining down the drain tube properly.
Each morning, turn your fridge off for 1 second and then back on again, and that resets the timer for the defrost, so that it won't occur. Do this each day to inhibit the self-thaw cycle and see if you still get the issue.
I also don't like to have the drain tube on the back side of the fridge draining into the black plastic catch container either. Often times the water can collect faster than it can evaporate and overflow is a risk. I am in the habit of routing the white drain hose/tube out one of the vent holes in the plastic fridge panel cover so that it just drips onto the ground.
2013 F-150 EcoBoost MaxTow, Roush tuned (415hp 506tq), lifted on 33s, R.A.S.
2013 Jay Flight 28BHS Elite (Equalizer 10K hitch)