Speaking incoherently by mumbling the first sounds that come to your mind while simultaneously tricking yourself into believing a ghost has inhabitated your body and that the crazy blabering noises are actually some spooky ghost language.
John: I was speaking in tongues at last weeks sermon
Pete: Oh, really? what did you say?
John: Blksdoihaflk hoidshaoif ilknflknvoi laskdf dflkjafl iosoahf golf.