Is my house haunted or something else?

I've always heard that dogs can see ghosts. Well, I have three dogs and one night, my family and I were watching a movie, and we paused it to go to the bathroom, and suddenly all three dogs who were laying in the same room started to growl and stare at the top of our stairs. We looked and saw nothing and then they started barking loudly and then returned to growling. Then, in perfect sync, all three dogs began to slowly move their stares down the stairs as if something was walking down the stairs. Our door is right at the bottom of the stairs and when their stares got to the bottom of the stairs they stared at the door for about 5 seconds and then they all just went back to where they were before. They had been growling the entire time through this, which took about 40 seconds. It was like something moved down the stairs and went through the door. The only other thing I can think of that happened in our house was, in the same room, a candle falling off of a table, even though I know the candle was at least an inch from the edge and it was in the middle of the night while I was awake and nothing shook or whatever. Is there a ghost? And yes, I do believe in them.