If you don't let it drop below that you'll be fine. Ghosts are popular because they're hardy, and a species that's fine at cooler room temperatures.
I've got a basic table lamp with a moon bulb. I suggest getting a lamp, and putting an Exo Terra Night Heat Bulb Reptile Lamp with a 50 watt bulb in it, because it's safe to leave on, and will up the temperature just enough to make them comfortable, without getting too hot, and the purple glow it casts is pretty neat, and won't bother you at night.
I use converted mason jars, so I don't like the idea of anything that touches the actual glass for fear of making it too hot.