I am a domestic helper in Hong Kong and I really want to visit WOW..

May I know which country you are from? Peole of some countries can get visa on arrival in SZ border. With the VOA, they can have a free visit in the city. While people from some countries have to apply for a visa in advance. For ur case, u can have the supporting letter form your employer and go to the Office of The Commissioner of The Ministry of Foreign Affairs of PRC in HK to get a visa. Or directly get a visa by asking help from an agent.