What does it mean when people are written on red paper and have numbers on the wall in Weinan, Shaanxi?

It should be to ward off evil spirits.

The black writing on the red paper should be for safety. If it is a talisman to ward off evil spirits, it should be yellow characters written on red paper, or red characters written on yellow paper. The yellow characters are usually written with gold powder or the like, symbolizing sunshine, and the red characters are mostly cinnabar, which wards off evil spirits.