Adam Gammon, from Forest Town, was reported missing on December 23.
And although he has made contact with a relative, officers are encouraging him to call them or visit a police station as soon as possible to confirm that he is safe and well.
Adam is described as white, 6ft 1in tall and of medium build, with a beard and glasses.
He may be travelling in a grey Peugeot 308 and may be in the Lincolnshire area.
UPDATE: Adam has now been found safe and well.
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