Story is: I bid on this 'ectoplasmic residue' on TradeMe, just for a laugh. There were other bids and the auction still had four days to run, so I was in no danger of actually winning it. Or so I thought. I was surprised to receive the email saying the ectoplasm was mine.
The guy selling it seemed a good sort, a Dr Who fanatic with his sense of humour well in place. I was happy to pay up and eagerly awaited the packet's arrival. It came with Ghostbusters-style authentication and a bit of back story. Cool!
The obvious thing to do, then, was to subject the ectoplasmic residue to some serious and rigorous scientific testing in the Strange Occurrences Laboratory.
Here is the result of the testing: Ectoplasmic Residue Testing Video