Midhya devi is the wife of Adharma (nearest English meaning is evil) in Hinduism. She is worshipped by spendthrifts and squanderers. In the Satya Yuga or Krita Yuga, she was not visible on earth because Dharma ruled. She could not be seen by people.
In Treta yuga, she was visible very little. In Dwapara Yuga, she was visible in many places but not completely. In Kali Yuga, Midhya Devi is completely visible and she is worshipped by many people. Adharma flourishes when Midhya Devi is visible completely.
People who are governed by ignorance, desire, lust, anger, jealousy, hoarding, and hatred are under the control of Midhya Devi. Those who are scampering for money, never satisfied with wealth etc and are always dissatisfied are knowingly or unknowingly controlled by this Goddess.
The brother of Midhya Devi is fraud.
It is said that she dances and makes merry when people practices extortion, graft, hoax, hypocrisy, scam, treachery etc.
Symbolically, Midhya Devi resides in all people. Those people who are able to bring out the good qualities constantly push Midya Devi down. She cannot control such people.