Strangely moving lights

At approximately 2:30 - 3:00 a.m. I noticed a faint light in the night sky in the north east. The light goes from being faint to about as bright as the bightest star in the sky in about 3 seconds. (Similar to if you turned a dimmer switch to the right). When it reaches ful brightness, it then slowly moves to the right (to the east) as if it's floating. It does this for about 4-5 seconds then dims until it's no longer visible. Roughly 3-5 minutes later, the light reappears the same way and in the same location it previously did. It will perform the same movement and disappear the same way as previously. Sometimes 2 lights appear instead of one. Sometimes the will move in the same direction in the same way. Sometimes they will appear and then go in opposite directions. I've been seeing this activity almost nightly for the past month when I originally noticed this.