'Isileli Palu, of Otara, was killed on August 3 while helping to put up tents at the family home in the village of Kolomotu'a.
The 36-year-old had been helping outside when he touched an electrical cord.
Tongan media are reporting a 49-year-old has since been charged with his manslaughter.
The Matangi Tonga newspaper said local police said the man charged is a power contractor.
The Herald is seeking comment from Tongan Police.