The Federal Bureau of Investigation, which has been paying extra attention to mortgage fraud in recent months, says it has uncovered a major surge in the number of schemes being perpetrated in the market. FBI officials say mortgage lenders have made more than 12,100 reports of suspicious activity so far this year, compared with only 4,220 in all of 2001. “It has the potential to become epidemic,” said Chris Swecker, an assistant director in the…