ggplot(data=tibble(f=1:3,x=1)) +
geom_blank(aes(x,x)) +
facet_wrap(~f) +
geom_vline(data=tibble(f=2, x=c(-1,1)*Inf), aes(xintercept=x), col="red") +
theme_bw() +
theme(panel.border = element_blank(),
panel.background = element_blank(),
panel.grid = element_blank(),
panel.spacing.x = unit(0,"line"))