BEIJING – Wei Guohua finally found his Mrs. Right – almost 10 years after he died.

Led by a rooster, Wei Guohua's children brought the remains of his bride and buried them inside his tomb in Yulin, a town in Shannxi province, on Nov. 14, 2012.

A well-known local feng shui master hosted a ceremony to pronounce them husband and wife. (The rooster was there because people believe the birds can guide the dead to a new home.)

The marriage of two dead people in China is a centuries-old custom called "minghun," or "ghost marriage."

According to folklore, if people are alone when they die, they will be alone in the afterlife, too. Worse yet, lonely ghosts might come back and try to take family members back to their world to keep them company. So it becomes a family responsibility to make sure deceased relatives are happily married.

Plenty of challenges
Carrying out a ghost wedding in modern China isn't easy. For one thing, it's not legal. The practice was officially banned after the Communist Party came to power in 1949, but it can still be found in remote regions of the country.

Also, ghost weddings can cost big bucks. They are performed much like regular weddings, except they usually involve a burial ceremony. Relatives and friends of the deceased eat and drink. Sometimes entertainment is provided. After the wedding, the two families typically socialize together, especially on major holidays. Some believe their bond can be closer than that of in-laws of living couples.

As is customary with a regular marriage, the family of the groom must give the bride's family a betrothal gift. When the couple is dead, that gift almost always comes in the form of cash. In total, Wei's children spent around $2,500 on the betrothal gifts to the bride's family, but they considered the price reasonable. A typical betrothal gift for a ghost wedding is between $4,500 and $5,500.

Finally, it's not exactly easy to find an available corpse.

The dark side
Demand for female bodies is particularly high. Professor Chen Huawen, an expert in Chinese burial customs, says the reason is that many young bachelors work as coal miners in provinces where ghost marriages persist. Coal mining is dangerous work that often leads to death. According to Chen, miners' families often receive a lump sum of around $50,000 as compensation when a miner dies in an accident, and they are often willing to spend some of that money to find a wife for their dead relative.

As a result, the fresh corpse of a young woman can fetch as much as $30,000 on the black market. That kind of demand has led to the grim crime of grave robbing.

In early March, four people were sentenced to more than two years for stealing 10 corpses from graveyards in Shannxi province and selling them on the black market.

Zhou Peng, a journalist at the Xi'an Evening News who reported on the story, told NBC the criminals even performed plastic surgery on corpses and dyed their hair to make them look younger, so they could fetch higher prices.

10-year search
It took 10 years for Wei Guohua's children to find a wife for him. The Weis began looking for a bride the day their father died in 2003.

Born in 1920, Wei was single after his first wife divorced him in 1960. A poor man with four young children, his prospects for a wife were slim. The children saw the difficulties their father endured to raise them and wanted to see him happy in the afterlife. They also believed a happy father could watch over the family.

The bride, Yue Caixia, had waited even longer. Yue was born in 1968 and died in 1989 when she was only 21. Her brother and sister were very careful about arranging the first marriage for their sister. According to the Wei family, Yue's last arrangement broke up because of disagreement over the betrothal gift.

But Yue's family could not wait any longer. The family planned to move away from where she was buried, and they dreaded leaving her alone. When the Weis' proposal came, they accepted it.

Yue had been too long in the ground for her family to fuss over a bridal coiffure or makeup. Instead, her family folded miniature versions of the series of dresses a Chinese bride traditionally wears into a new smaller coffin. They donned gloves to transfer her bones gingerly into her new home. They worked beneath a canopy to keep her remains from the daytime sky, which is considered harmful to the souls of the dead.

Even though the event is somewhat celebratory, since the practice is banned, the families did not take any photos. 

And it took a long time coming, but Wei's family was happy with the arrangement.

"Ghost marriage between two dead people is stable and lasts forever," said Zhao Ming, one of Wei Guohua's grandsons. "There is no such thing as divorce."

NBC News' Huang Pei contributed to this report.

Related: 

Read more from NBC's reports on China in Behind the Wall 

China river's dead pig toll passes 13,000 but officials say water quality is 'normal'

Coca-Cola not 'illegally mapping' China after all, officials say