jb, you make a good point but there have been MANY people who have taken photos and invited parapsychologists and ghost hunting teams to investigate. Of course there will never be any agreed upon proof because all of this is subjective.
When we get to the point where everyone can agree on a definition of what a ghost is...that will be a step toward accepting "proof". It will be THE sky is blue moment. The sky isn't green or orange or purple. We call that color blue and we all agree that color is blue. In terms of the paranormal, people just don't agree on anything right now. Could it be that someday the existence of an afterlife will be proven? Doubt it. It's personal choice.
You believe in God, I don't. You don't believe in ghosts, I do. How odd is that?
If there is a great plan placed upon us by a great creator...well he/she certainly has a sense of humor. Otherwise, we'll find out when we find out (after we've passed away). Or not.
Mortal humans created religion and science to make structure and sense out of their world. Explain things they couldn't explain. Otherwise, life might be maddening.
Whether you take the scientific approach or the spiritual approach it's the same thing. Both are looking for answers and if you find comfort in believing in God or believing in ghosts...it's all good.
Many children honestly believe in Santa. Most adults don't. But once upon a time the naivete of youth allowed for a sense of wonder. This way of making sense by believing changes over time, this desire for proof grows stronger with age. Some people find their proof and are content. Others wander and wonder in a constant state of maybe. That's life's journey.
In my journey I've come to believe in the afterlife, in your journey so far you believe in God.

to both of us. In one small way, we've found our comfort and solace. Feels good? Does to me.