To provide a weep hole shape of a housing that prevents rainwater from entering the housing.

As for the shape of the weep hole 9, a water passage 10 which penetrates a bottom surface 4a and a swell part 8 of a front cap body 4 nearly vertically is spot-faced from the reverse surface of the swell part 8, and a diameter-increased stage part 11 is provided to form a diameter-increased hole 12, which is opened below the swell part 8; and then the water passage becomes long and the depth of the diameter-increased hole 12 of the weep hole 9 can sufficiently be secured to securely prevent rainwater from entering the housing 2. Even when the bottom surface of the housing 2 is made slightly thick and a weep hole in the same shape as the weep hole 9 is directly formed, it can easily be inferred that rainwater does not enter the housing 2 by reverse flow through the weep hole.