Can you cash in a life insurance policy that you pay premiums on at work?

It depends on the type of life insurance you are buying. Basically, if it's a term policy, no. If it's a whole life , then yes. There are other variables that can affect this (e.g., any conversion limitations).

Most employer plans are Group Term Insurance, but there are some UL or Whole plans. First step is to see what kind of plan you are in. Then you should have a copy of the policy. If you are trying to take cash from the plan, contact the company that wrote the plan.