Being trapped, or buried alive, or tightly squeezed in to a small space are all horrific things to dream about and they are said to have negative meanings when it comes to real life situations. Nightmares like this can mean a number of things, most obviously that you feel trapped in some way - perhaps you are stuck in a job you hate or are being pressurised in to doing something you don't want to do, but you can't escape said situations because you feel as though the consequences would be even more dire. Another interpretation of the dream is that you may be holding on to old habits and the dream is telling you that you need to shed them in order to remove a negative from your life and move on, becoming stronger and more fulfilled in the process - perhaps you've been doing something since you were a child that no longer serves a purpose in your adulthood, or perhaps you smoke or drink habitually and need to stop. Either way, take it as an alarm or a wake up call and respond to it accordingly. Finally, if you are literally trapped in a "box" in your dream, it could be advising you think outside the "box" in real life. Perhaps a situation in your life that you aren't enjoying could be rectified by doing something unexpected or even irrational. For the record, the same meanings are said to stem from nightmares about drowning - which essentially amounts to the same thing as being trapped (more on the potential meaning of drowning in dreams later on in this article).
