i have had success with a grommet round the hole as the wires enter the mast [to avoid chafe], then supporting the wires with a cable tie attached to the 'lid' of the mast if the hole is on the side, or cabletie the wires to an upstand for the light/wind wand maybe, then sealing around the wires at the point where they enter the mast with silicone.
2 cents delivered
Rob