Units responded to a reported alarm sounding after a lightning strike. The homeowner had arrived home to find his CO alarm sounding and found that his shed had been hit by lighting. FD units checked the house and found elevated levels of CO coming from the generator, which was running outside an open window. FD units ventilated the house and investigated, and found that the well pump breaker was also blown, and that the water well was the original location hit by the lightning. FD units secured the breaker and advised the homeowner to contact his service provider.