Pluto is an object inside of the solar system, and it is therefore considerably less than 1 light-year away; the distance varies from 4.25 to 7.4 light-hours. Pluto's distance from the Earth varies because both celestial bodies follow elliptical paths around the Sun.
Pluto's distance from the Sun varies from 4.4 billion km at perihelion to 7.29 billion km at its furthest point. Earth has a less elliptical orbit and tends to be 150 million km from the Sun throughout its orbital period. The maximum separation between the two worlds occurs when Pluto is at its aphelion and the Earth is on the other side of the Sun. The closest approach comes when Pluto is at perihelion and the Earth is between it and the Sun. In the first case, the separation is 4.25 billion km, and in the second it is 7.44 billion, or 4.25 to 7.4 light-hours.