The phrase "a most strange" is correct and usable in written English.
It can be used to emphasize the peculiarity or unusualness of something, often in a literary or formal context.
Example: "The old book contained a most strange tale that captivated all who read it."
Alternatives: "a very strange" or "an exceedingly strange".
"It was a most strange and curious household," he said.
In life as in fiction: the body of Eva Peron, the Argentine leader's wife, suffered a most strange fate after she died in 1952: disappearing until being rediscovered in Europe in 1976.
I'm hoping to join my two-year-old grandchild in Portofino for a few days and I want to read Francis Spufford's Golden Hill (Faber £16.99), and Unholy Land (Skyscraper £16.99), a most strange, ambitious rap romance set in Israel/Palestine, composed by Aidan Andrew Dunn, a poet and musician known as the William Blake of King's Cross.
Soon, the story took on a life of its own, and in 1642 it was printed in London under the title Newes from New-England of a Most Strange and Prodigious Birth, brought to Boston in New-England... Though the author of this work was not named, it may have been the New England minister Thomas Weld who was in England at the time to support New England's ecclesiastical independence.
(Dedicating "Shadow and Act" to Sprague, Ellison immortalized him as "A Dedicated Dreamer in a Land Most Strange").
Michael Kimball has an uncanny ability to parse the most strange and painful parts of being a person into something most anyone could comprehend.
I am struggling to work out what I find most strange about the pulverisation of a wind turbine in Grainsthorpe, Lincolnshire.
Unless most strange twists occur, the Knicks are a lock for the No. 3 seeding.
"The most strange and bizarre way to pick up a trophy," said Paul O'Connell.
Rainer Maria Rilke gave luminous expression to this idea in his Letters to a Young Poet, by saying that we need "courage for the most strange, the most singular and the most inexplicable that we may encounter".
By far the most strange oil-removing item on this list, a heavy application of cheese whiz will break up oil stains in a jiffy.
