How to get rid of a water bug (Oriental Roach)?

One came inter my room and now it keeps hiding and I can't find it or kill it. There's a certain spot it's found now that I can't find. By waterbug I mean those big glossy black ones. I don't feel safe to do anything until I can get rid of it but I can't even find it now. I don't want this to grow into a problem. Any help?