years ago, there was a home hair cutting gizmo called a "flow-bee". it was a thing that i think, held a couple of single edge razor blades. you set it to the desired length of hair you wanted, then ran it through your hair like a comb. my one buddy always had short hair, and he would use that to tune up every now and then. don't know if that thing is still made today, or not. like the saying goes : "as seen on TV !"
