The "logical" part of me wants to say no, but I've had quite a few weird experiences. Here are a few.
My husband and I had a Yorkie for 14 years. Eventually he was having so much trouble due to his age that it was time to let him go. Our county's animal shelter puts elderly pets to sleep at no charge, using the same procedure that the vets office does, so my husband took him there at our vet's recommendation. I took it hard. He was my child. Fast forward about 6 months. I decided I was ready for another baby, and wanted to adopt a kitten. We went to the animal shelter, where we found the sweetest, most affectionate kitten EVER. She'd been born at the shelter, and she clung to me like glue the moment we got her out of the cage. She made it perfectly clear that she was going home with me! On the drive back home, she stayed snuggled up to my neck, and wouldn't even turn away from me to look out the window. I was hers.
For a good 6 months after we got her home, I'd see our Yorkie going around a corner, but when I followed him, there my sweet little cat would be. It happened almost every day. One day something occurred to me. I sat down with a calendar and starting counting. She would have been born at the shelter on the EXACT DAY that we took our Yorkie up there. Did our Yorkie find his way back to us? I don't know. But even now, years later, our precious little girl kitty loves nothing more than to be held and cuddled. Maybe two pets are sharing one body ... I don't know.
Another one: We live just a few miles from Chickamauga Battlefield, and often ride our recumbent trikes there. We've had LOTS of odd experiences there. My husband and I both heard civil war drums at the same time. We've rode our trikes through "cold spots" where the temperature dropped drastically. I've heard a lady coming up behind me, presumably a jogger who was talking to a friend, and when I turned around nobody was there. My camera has zoomed all by itself. I took a photo of an empty field once, and in the field were two green glowing objects at about eye-level (there is a legend about "Green Eyes", some sort of entity that lives in the park). It was probably a trick of the light, but it was still very eerie.
You know those glass "plasma balls" where you can touch the glass and the "plasma" will reach out toward your finger? Imagine a blue sparkling "plasma ball", without the glass. My husband and I both watched, with our jaws on the floor, as a blue "plasma ball" came in through the top of our (closed) sliding glass door, went along the wall near the ceiling, turned the corner, and disappeared without a trace down the hall. It made no sound, and didn't leave any markings on the wall. We still don't know what it was.
I've also seen odd things in the sky in several occasions, and even found physical evidence of one of them ... and odd white rock with blue speckles that appeared to be very, very dense melted plastic. I added it to my rock collection, which my mom threw out without my knowledge when we moved (I was 9 or 10).
While I can't say for sure that I believe in ghosts, I do believe there are a LOT of things out there that we don't understand.