Quite often a home inspector will see white wires attached to the breaker, as in the photo on the left.
Wires (conductors) are coated with plastic insulation colored either red, black, white, or green. Red and black are typically used for the positive or “hot” leg of the circuit, while white and green are reserved for use with the neutral and ground legs, respectively. Often, ground conductors are left bare.
Sometimes an electrician will use a white-coated wire as a positive conductor in a household circuit. I see this most often with air conditioner circuits. This is not a hazard in and of itself, but the electrician is supposed to mark that wire with black or red tape to indicate it is being used as a positive conductor to avoid confusion. The Texas Real Estate Commission requires inspectors to note such improperly-marked conductors as a deficiency, so it shows up commonly.
When I see it, I recommend that the wires be labelled by an electrician the next time work is done inside the breaker box. Otherwise it is not a matter of undue concern.