How to avoid commitment in an interview?

I have an interview scheduled in a few days for a job that I'm not entirely sure I want. Basically I have to decide whether to take a job that might be really soul-sucking and time consuming or continue building momentum in my freelancing. I honestly don't want to do the interview but I've been passed over for most of the jobs I've applied to so I feel like I should take SOMETHING even if it isn't exactly what I'm looking for. I know I have a solid chance at getting this job, so how do I avoid committing myself to the job during the interview? Is it acceptable to tell them that I'll let them know if I accept the position in a few days? This is my first "big-boy job", if that makes sense. Thanks for reading!

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