Here is what I found on dialog:
Dialog is a utility that allows you to show dialog boxes (containing
questions or messages) in TTY (text mode) interfaces. Dialog is called
from within a shell script. The following dialog boxes are implemented:
yes/no, menu, input, message, text, info, checklist, radiolist, and
So, it looks like you could safely kill it (ps aux to find the pid, then kill PID). Might want to see if you can track down which app called it or see if you can fix dialog by updating it, etc.