(St. Paul, MN)  --  It's hoped a wet weather system moving into Minnesota will moisten the state and reduce the wildfire threat.  In the past several days, the D-N-R has reported 36 wildfires being fought over the upper two-thirds of the state.  More than two-thousand acres have burned with the quick disappearance of snow this spring.   A dozen homes and a number of businesses in the Perham area had to be evacuated Thursday after a large grass fire spread quickly.  Otter Tail County Sheriff's Lieutenant Mike Boen says no was one hurt and there was no major damage. The D-N-R used an airplane and a helicopter to assist fire crews on the ground.