My house is 38 years old but I have only lived here 6 years. There were no visible ceiling cracks at the time. In the last year, 5-6 long ceiling cracks have appeared. Some might call them cracks from settling but I'm concerned. The house is a ranch with a basement that runs below the main floor. There is a partial attic, too. Location is northwest of Chicago. Is this something to be worried about since the appearance of cracks is so sudden and there are multiple cracks?