Bhairava is not a sort of Lord shiva, but a type pretty closely involved and he is without doubt one of the powers assigned through the Lord. It's the custom made that the keys with the temple are submitted to bhairava after the pujas are concluded for the working day https://getsocialsource.com/story4044583/how-much-you-need-to-expect-you-ll-pay-for-a-good-bhairav