Between the years 2003-2005, I worked in a boarding/grooming kennel in Crownsville, MD.
It consisted of two buildings, the grooming shop and the actual kennel. The grooming shop was surrounded by the parking area and the kennel was behind the parking area. The kennel, the dog runs and the play yards were all surrounded by six foot high privacy fence.
When I first started working there, I noticed some odd residuals. Sometimes you would be in the kennel building and see a shadow flicker in front of the glass on the door, but no one would come in. The gate latch was attached to the side of the building, so you could hear it every time someone opened the gate. Sometimes the gate would rattle, but no one would come through.
Some of the other workers claimed it never felt like you were alone, but when you were alone, it was with 50+ dogs so I'd take that with a grain of salt.
I noticed this stuff, but never paid it much mind until I came in for the morning shift. The other two workers were sitting on a bench by the gate smoking a cigarette before they started. I could hear someone walking across the gravel in the dog runs. I asked who was back in the runs already. The other worker - let's call her Sam - said 'No one's back there.'
I pointed out that I could very clearly hear someone walking across the gravel and Sam replied 'I know. But there's no one back there.'
I went up to the gate and waited until the footsteps were on the other side, then opened the gate. There was no one there. Sam grinned and said: 'Told ya!'
Once we had the dogs taken care of for the morning, we started discussing the odd goings on and came to the consensus that the kennel was probably haunted, but there wasn't much we could do about it.
After this realization, the 'haunting' increased from residual stuff to a full blown haunting.
By ghost dogs.
Being a small kennel, we developed 'regulars' who came every other month or so and we got to know these dogs by name. One of them was a beautiful Redbone Coonhound by the name of Copper. Strangely enough, Copper started showing up in places he shouldn't have. He started being sighted even when he wasn't there.
A worker came back to start her shift and reported with a smile that 'Copper's back! He's out in one of the runs.' I checked the schedule real quick and stated that Copper wasn't there. He wasn't even on the schedule for the entire month. She replied that he was and I should go check if I didn't believe her. I stuck my head out of the door and saw that every run was empty. She came right behind me, saw that they were, and started spluttering that she had just seen Copper - or at least another Redbone Hound - sitting in the first run.
Another time, Sam was sitting up front while I folded laundry. The dogs had been out for their morning playtime and had been fed, so most of them were curled up in their kennels, napping. Sam suddenly looked out of the door, grabbed a kennel lead and ran outside. She came back after a second and blurted that Copper was out and running loose through the grounds. From where I was standing, I could look straight into Copper's kennel (the favorites usually got a space up front). He was curled up dead asleep.
Sam shook her head and said, maybe it's not Copper, but there's a Redbone Hound running around loose. I grabbed a kennel lead and went out to help her. We searched all through the kennel grounds (about two acres) and there was no mystery dog.
We would let the dogs out in playgroups together. The larger dogs only had groups of four or five but the little dogs generally got along very well and we could let them out in a big group of ten to fifteen. When we let them back in, we would just open the door that led to the little dog yard and let them all run in, then catch them individually and put them in their kennels. The smarter dogs figured out where their spot was and would just go and wait for someone to let them in.
We let the little dogs back in, then went around catching them up. A pair of toy poodles shared a kennel in the back so I went back to put them up. I caught the first one and lifted him into the kennel, then picked up his kennel mate and put her in. As I'm latching the kennel, I hear little toenails run up behind me and I felt a twenty pound dog jump up against the back of my leg. Thinking it's just one of the other dogs that wasn't caught yet, I say 'Okay, okay, you're next.'
I turn around and there's no dog. Not only is there no dog, there's just a long corridor leading to the front of the kennel building with no places for a small dog to hide. All the other dogs had been caught and put up by the kennel workers - the two toy poodles were the last loose dogs.
I never did any research into the kennel, but rumor was that it used to be a puppy mill twenty to thirty years previously and a lot of dogs had died on the property.