A 7-year-old boy was getting ready for bed Saturday night at his Costa Mesa home when he smelled smoke. Then he saw fire in the garage and ran to tell his dad, who had already fallen asleep watching television. “He had to shake his dad to wake him up,” said Costa Mesa fire Capt. Chris Coates. The man, William Rimmer, opened the door leading to the garage at his house in the 3000 block of Warren Lane and saw there was a blaze.He closed it and both he and his son, William II, got out of the house. The garage was well involved with flames which were spreading to a motorhome on the driveway and a neighbor’s storage shed, Coates said.