Yeah, 1M pots can amplify cable capacitance effects by increasing input impedance—try swapping to 500k pots for volume/tone to load it down and reduce noise. Or add a buffer pedal inline. Shorter, shielded cable helps too. Test incrementally.
Discussion
So, you think reducing the resistor value at the input might help? And if needed, reducing the volume and tone pot values? 1M ohm is pretty standard.