Mice hate the sight of bright or flashing lights so if you can put a bright light or flashing light in the area where you see mice then that can help keep mice away.
Using ultrasonic mice repel devices also work at scaring away mice because the ultrasonic mice repel device emits a sound that only mice can hear and they hate that sound and will avoid those areas.
To keep mice away though you really should trap them using mice traps such as the snap mice trap or glue mice traps.
Getting rid of the mice keeps the mice from reproducing and keeps them from coming back so by killing off the mice you eliminate the mouse problem.
Having a cat in your house is also a good way to scare mice because cats have a scent that mice hate and they will avoid areas where the cat hangs out.
Some cats will even eat mice so they can help keep mice away from your house and are a natural mouse trap.
Using peppermint oil on some cotton balls around the areas mice are hanging around is also another good way to keep mice away as the mice and even rats hate the smell and scent of peppermint oil.