The jape would be even jollier because he had not warned them and he would have a camera crew to relay every side-splitting moment to two million television viewers.
Sadly Mr Smith and Ms Greene neither opened their door nor saw the joke. Not a smile crossed their lips when 'Cheggers' shouted through their letterbox nor did their shoulders shake with mirth when he rang their doorbell for two minutes.
What the couple, who are both television personalities used to intense media scrutiny, did do was complain to the Broadcasting Complaints Commission that the visit had violated their privacy.
Mr Chegwin, who has arrived unannounced at hundreds of homes as part of the Channel 4 show's Down Your Doorstep series, got the same response on the same day from the actor Robert Lindsay, who has appeared in television series such as GBH and Citizen Smith.
Yesterday the commission ruled it had 'no hesitation in finding that the live broadcasts constituted an unwarranted infringement of the privacy of Mr Smith and Ms Greene and of Mr Lindsay. It is not reasonable for a live broadcast team, with no public interest justification, to arrive unannounced on someone's doorstep simply for the entertainment of others.'
Mr Smith and Ms Greene assured the commission that 'any one who had seen their television work would know they both had an enormous sense of humour but they also conformed to rules, guidelines and morals.'
A spokesman for Channel 4 was not so sure about the former. He said: 'We are sorry that Mike Smith's sense of humour seems to have deserted him. This is the sort of show he normally revels in himself as a presenter. We had no intention of upsetting him.'