Yes, we should believe in ghosts or spirits. The Catholic Church & the Bible plainly teach that they exist. Ghosts/spirits can give helpful information (II Mac. 15:12-16). They can announce God’s judgment (I Sam. 28:15-20; cf. Sir. 46:20). They can be good and holy (Mt. 17:3). However, they can also be evil, consequently, [color=red:3q1ihlj4]we are not to attempt to contact them [/color:3q1ihlj4](Lev. 19:31; 20:6, 27; Deut. 18:10-11). We should let God use them to inform us of His will and not try to gain some advantage by contacting them when we wish to.
The beatific vision is seeing God face to face. A Biblical example is seen in the calling of Isaiah to be a prophet (Is. 6:1-5). The beatific vision usually refers to seeing God in heaven. St. Paul speaks of this, “For now we see in a mirror dimly, but then face to face” (I Cor. 13:12).