Smith is in immediate need of medical attention and is believed to be suffering from dementia or some other cognitive impairment, authorities said.
He might be walking on the side of a roadway, highway or interstate. Officials were unable to provide a description of his clothing.
Smith left his home at 3044 Farmlife School Road sometime after 10 p.m. Thursday and prior to Friday morning.
He left a note stating that he was going to his grandfather's home in Siler City. However, his grandfather is deceased, authorities said. Smith does have other living relatives living in that area.
“At this time, his direction of travel is unknown but he is on-foot/walking and does not have access to a motor vehicle,” according to the Silver Alert.
Smith is white, 5 feet 8 inches tall, 170 pounds with brown hair and hazel eyes.