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Prophet Joshua Iginla of Champions Royal Assembly Kubwa can be of help. He has this special ability common with this association of African Prophets and Apostles, to invoke the Spirit of your grand Dad into you. He will command the Spirit to speak out by "fire on the leg and fire on the hands" Your grand Dad will actually say a lot under fire which will be recorded in tapes that you can purchase thereafter.
Know that God abhors consultation of mediums or Clairvoyants by Christians, There are many others around you but they no longer go by the name Clairvoyants, they prefer to be called Prophet Dr or Apostle Dr.
Goodluck

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