If you are on full disability can you go into a home based business?

You need to check the definitions in your policy related to "Own Occupation", "Any Occupation" and the definition of "disabled". There are also time frames - 2 years for this, 5 years for that... specified in the policy.

Furthermore, if your reference to "on full disability" is referring to Social Security Disability (rather than a private disability policy), there are other applicable limitations on earnings so as not to disqualify you from or reduce SSDI payments.