The postcard was sent during an apparent canal holiday in Cheshire
The Williams family ran the Prince Albert pub in Gloucester, close to the home in Cromwell Street where the Wests imprisoned, tortured and killed young women, including their own teenage daughter Heather.
The postcard, dated October 1990, was addressed to "The West Williams Menagerie" and appears to be written with several sexual innuendos.
It includes a line: "Colin says the 'birds' are very friendly here. Loads of wildlife."
It is signed: "Mum and Dad xx."
It is signed: "Mum and Dad xx".
The Wests appear to be on a canal holiday in Cheshire, although the card is postmarked from Gloucestershire.
The postcard was given recently to Andy Jones, who runs the Crime Through Time Collection at former Littledean Jail in Gloucestershire.
The postcard is dated October 1990
He said: "The hairs on my neck stood up when I was given this card. To my mind, it tells of an orgy."
The Wests were arrested for murder in 1994 after police found remains of missing young women buried in their cellar and garden.
Police are now excavating the garden of the Williams' former Devon home
Fred hanged himself in prison before his trial.
His wife was jailed for life for the murder of 10 young women after implicating Fred.