You had a professional change the spark plugs in your 1999 Ford Contour now the timing is off and the dome light stays on how do you fix this?

While I won't say anything is absolutely impossible, I can't think of a plausible connection between these three items. How do you know the timing is off? Have you measured it? Is that your way of saying it's not running right? If so, what are the exact symptoms? If the dome light has a switch attached to it, make sure it's not in the "always on" position. If it doesn't have an integral switch, check the dash illumination dimmer switch -- many of them have a "dome light always on" position they click into at the full brightness end of their range. If that isn't the explanation, the next most likely thing is one of the door switches is faulty.