I checked this forum 5 minutes ago on my phone from bed, but I felt inclined to go get my laptop and respond :)
When meditating, do you listen to any calming/relaxing music or do any guided meditations or just sit silently? If you haven't tried any guided ones, I recommend them, especially to someone who is already tuning in.
I would also look into any development groups in your area. Its basically what my class was. Its just a small group and you try to read them and contact people in spirit. We started with meditating, then attempted contact. Some people in the group made some pretty amazing connections.
I'm curious, do the voices frighten you at all?
I would try asking the voice(s) mentally who they are, what they need, etc. Try that a few times and when you ask, quiet your mind as much as possible and that will make the connection easier and more clear.
Yes, signs are an amazing thing when it comes to people in spirit! I for one know my grandmother sends us butterflies and a few mediums have told me this! Ever since the first one mentioned it, butterfly things, including real butterflies that never used to be around my house, show up everywhere!
I've also had experiences where electronics in a house go nuts. It wasn't my house( thank God :)) but my aunts house on Xmas eve 15 or so years ago and my uncle( her husband) recently passed away. When the lights started flickering, we all said hi to him!! One thing I've noticed thru experience and research is that spirits like to be recognized.
I have a few decks of oracle cards myself! I just love the pictures on them too...so beautiful!
If you have any further questions/comments or just want to talk, feel free to PM( private message) me :)