pH sensor box - ADS1115
Breadboards are notorious for loose, wobbly connections.

They are also known for having high resistance contacts and stray capacitance between connections.

It probably doesn't help much to have long wires connected your breadboards, with the wires run up around that Node MCU module with its wifi or bluetooth antenna.

Pretty much all of your wiring (breadboards and terminal blocks and long wires near a transmitter) says "make a mess of my signals, please."

Another thing is that typical 5V USB powersupplies a generally very noisy.  Depending on whether or not your ADC and pH board have their own regulators/filters, you may be getting a lot of noise that way.