You know what, you might see ghosts, have weird experiences, know there is a 'presence' around, whatever, I know I have experienced those things, my daughter also, we have even experienced them together so these things are defintely not just my imagination, that would be simple but unfortunately it's not the case. However, when it comes to spirits of the dead you probably do no not want to actually communicate or associate yourself with them. They are what is known as 'unclean' spirits and can make your situation much worse, including your health and sanity. I realize that they are not all intrinsically 'evil', but they are far from holy also.
Breaking a generational bloodline with a spiritual hold on it can be difficult, my mom was (lightly) involved in the occult when I was younger, my family a long line of very superstitious catholics with all sorts of odd east european beliefs, I sort of went through that when I gave my life to Jesus as an adult. It took a good few years to finally come to a place of peace where they no longer tried to assert themselves, may be one of the major reasons we have some mighty angels round here.
You may have a familiar spirit that has been in your family for years which is why someone would tell you you have the ability to contact the dead. Personally I think everyone has that ability if they so desire but I wouldn't go there. Binding yourself to spirits on that level will never give you the peace and wholeness that God has prepared for you if only you reach out to claim it.
I would be interested in hearin about the wiccan stuff too. Not that I enjoy that, I actually abhore the idea of it but I have never spoken to a wiccan personally, have only read about it. I obviously have my opinions of that already, and what the Lord has shown me about it probably because of associations in my extended family on that level, so you might have to endure me.
What I experienced with the mercury poisoning was far beyond my worst nightmare. The adverse health effects, the numb brain, the bad attitude, mercury rage as I call it... but I know myself and I know that's not me, I could feel the mercury running in my blood at times, could sort of hear it even like a whirring sound in my veins, absolutely dreadful and very very scary. I also agree counseling is useless... what helped me most was chelation, it's not a mental problem even though it affects behavior. However, I often read this board and notice the high ratio of such complaints from non-christians as compared to people like myself who believe or know that the Lord is nearby to comfort, heal, and give peace. I often think that maybe some of these people have spiritual problems as well as heavy metal poisoning.