Oil or gas?

I am watching a television programme about two people competing against one another in buying old things and making a profit from re-selling them when the doorbell rings.
The show is about to announce a winner. I think my champion will win against the other person, neither of whom I know or care anything about.
There is a man in a short blue raincoat standing in the darkness outside my front door. He carries a clipboard and what appears to be an ID tag flapping across his breast on a string.
He hails me and asks: if I use oil or gas to heat my home? I ask why ? and he smiles and says not to worry, he is not selling anything.
He repeats the question with the breeziness of the totally programmed.
I ask his name; he says it does not matter, it is of no account.
I say, I have to close the door if he will not tell me who he is or what he wants.
But, he walks away into the night leaving me with an opened door and a confused mind.
The show is over when I sit down again and I don't know who won.
And I don't know what oil or gas wanted, either.
I ask around, but nobody else saw him.
I wonder if I dreamt him, this man with no name and nothing to sell who called to my home from the darkness when I least expected him.
Storytelling here