Should I take a salary job when I know I probably won't be there for more than 4-6 months?

I know that I will not work for this company for long and I will immediately quit once I get a school date for my federal agent program. However, in the meantime I need to be working and earning some pay. Is it wrong to accept this new job when I know I will be out the door in a few months? I feel kind of bad about it, but on the other hand I deserve to pursue the job that I really want.