My boyfriend bought his home in 2008 and I moved in early February of 2010. When I came to live with him, he had 3 cats and I brought my cat with me. We had one tortie, one calico, one white and one orange in coloring.
Shortly after moving in, I noticed some rather odd things occurring. Such as meowing coming from a room that none of our cats were in. However, having several cats, I just shrugged it off. One morning, my boyfriend was getting ready for work and I was laying in bed. The cats were not allowed in our bedroom because of allergies, so when I heard meowing coming from under the bed, I asked my boyfriend to get the cat out from under there. We visibly saw the bottom of the comforter moving as if something was walking behind it, but when he got down and looked, there was nothing under there.
He then went out into the family room but left the door open. I felt something bumping the bottom of the mattress and told him that she (one of our cats) was back under there. He came back into the room and told me that all four cats were asleep on the couches. After hearing that, I quickly checked and found nothing.
A few days later, I was sitting in our family room on a couch that faces our bay window. Under the window are two mirrors at the back of two storage cubbies. I have long sheer curtains that hang in front of the cubbies. I noticed the curtains were moving a bit, but it was the middle of winter, so no windows were open. I glanced at the curtains and in the mirrors, I could see the reflection of a little brown tabby cat, but couldn't see the actual cat. Needless to say, I was a little freaked out about that.
Since then, we have down-sized to two cats, both of which are predominately white. I have see this little brown tabby on several occasions, as well as a large black cat. The brown one I usually see out of the corner of my eyes or will see it dead on, but by time I blink, it's gone.
The black one, however, I see much more often now. And he (I don't know for sure, but it looks like a 'he' to me) lingers before disappearing. About three months ago, he was just sitting by the front door.
And just a few nights ago, I was on the phone with a friend of mine, walking from my kitchen to my family room when the black cat walked right in front of me and disappeared into the wall next to my half-bath door. And my two-year-old son seems to also see him since he follows him saying "nice kitty" even when I can't see the cat.
I've gotten used to seeing them randomly, so they no longer alarm me. And even them being "ghost cats" doesn't scare me. When I hear random purring even though neither of my cats are in the room, I just kind of smile. It's kind of good to know that they're content even after they've passed on.