Odiham has had several unexpected visitors; I did a fam flight with Britannia Airways once and the FO told me he had been positioning to Lasham in a '737, they landed and taxied in and as they came to a halt, the marshaller turned his bats round to reveal 'Welcome to RAF Odiham' on the reverse. Then there was the Rumanian An12; being vectored for runway 07 at Farnborough, the crew saw runway 10 at Odiham and in spite of the controller telling them it was not Farnborough, they landed!
The aforementioned Twin Otter definitely should not be included. It was a scheduled flight into Gatwick but routing outside CAS; once on Farnborough frequency the pilot advised he had an engine problem and needed to land quickly (I think he had to shut one down) so was vectored for visual approach at Odiham.