It is hard to imagine that anyone would take advantage of people whose lives have already been thrown into turmoil by the tornadoes that hit Tennessee, Georgia, Alabama and other Southern states. But it's happening.

There have been scattered reports of looters spotted amid the rubble of destroyed homes. The sheriff in nearby Dade County, Ga., for instance, was in a helicopter surveying the damage when he saw someone rummaging through the wreckage of his own home! Thus far no one has been arrested in that case.

Meanwhile, authorities throughout the region are warning people about home repair scams. Of course, there are many legitimate contractors who are working tirelessly to repair damaged homes or replace lost ones. But authorities advise caution when a repairman shows up unsolicited, or is from outside the area.

Unscrupulous repairmen may offer attractively low-priced repairs, but demand partial or full payment in advance. They might do a poor or incomplete job, or they might take the money and run, leaving the homeowner even worse off.

Some tips to help you avoid becoming a victim of home repair fraud include:

* Get several written estimates for the work before hiring anybody.

* Request local references for work that the repairman has already done - and check them.

* Get a clearly spelled out contract specifying all the costs, the work to be performed and other details before paying for anything.

One other rule of thumb certainly applies to any offer of repair work: If it seems too good - or too cheap - to be true, it probably is.