i recently bought an older hot tub, it has a built in gfci box on it and when the tub is running and everything is on, i can push the test button and it kills everything does this mean its working like it should ??...my house was built in the 1960's so it doesnt have the gfci outlets..my question is does this sound right i dont want to be shocked while i'm in the tub, i have stuck my finger in while turning stuff on and off and no shock but i want to be sure that if there is one the little gfci box is working properly....thanks for any help