The strapping centre-back will make the perfect replacement for Dave Marden who has left Sholing to return to local football due to work and family commitments.
Castle – who joined promoted Sydenhams champions Winchester during the summer - is the third big name to have left the club in the past week, following Leigh Mills and ex-Saint Tom Dunford out of the Denplan City Ground.
His departure continues what owner Paul McCarthy describes as “a bit of movement” at Winchester in the wake of costly exits from the FA Cup and FA Trophy.
Wishing Castle all the best at Sholing, McCarthy said: “I wish him all the luck in the world.
“Pete’s got work commitments and he’s joining a club closer to home.
“He’s done great for us and I hope he does well for Sholing – but not against us!”
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