I have also heard many politicians spreading the myth that there is rampant welfare fraud. The truth of the matter is that outright fraud is very rare. A quick google search turned up some figures for food stamps:
"The U.S. Department of Agriculture, which administers the food stamps program, said 3.8 percent of benefits were paid in error in 2011, according to a factcheck done by PolitiFact Texas in June 2013. The error rate covers both overpayments, including fraud, as well as underpayments. Caseworker mistakes, rather than fraud, were the primary cause."
PolitiFact | On average, 20 to 25 cents of every $1 spent on four government assistance programs is lost to fraud, Sen. Ron Johnson says
3.8% of benefits are paid in error, and this includes all errors, from clerical mistakes to outright fraud. Therefore, fraud probably makes up about 1% of the budget assigned for food stamps.
Conservatives like to vilify the other 99% of welfare programs based on that 1% fraud. That's sickening, and they shouldn't be allowed to get away with it.