Dear Rosa:

Well, wearing any religious sacramental or symbol "just for show" is improper. Unfortunately it is a common thing to see Rock Stars, gang bangers, and other reprobates and irreligious people wearing a Cross or Crucifix. In that context I think it is sacriligious.

However, some people may wear the Rosary or some other sacramental or symbol not "for show" but as a statement of their faith and/or to remind themselves of who they are as Christians -- even though they may not pray the prayers associated with that sacramental or symbol. This may not be the best thing, but it is not a sin either.

The symbols we wear should reflect our inner devotion. It is important to wear external things. St. Louis de Montfort said about this:

Although what is essential in ... devotion consists in the interior, we must not fail to unite to the inward practice certain external observances. “We must do the one, yet not leave the other undone” (Mt 23:23); because the outward practices, well performed, aid the inward ones; and because they remind man, who is always guided by his senses, of what he has done or ought to do; and also because they are suitable for edifying our neighbor, who sees them; these are things which inward practices cannot do.

God Bless,
Bro. Ignatius Mary