If you break your lease early, a landlord has a duty to mitigate damages. What this means is that the landlord must take reasonable steps to rerent the premises in a timely manner. Once the landlord finds another tenant, your obligation ends are you not liable to anymore rent. You may still be liable for damages done during your tenancy.
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I agree with Attorney Kluck's answer, above. Please note, however, that there are some illegal provisions which render a Wisconsin residential lease void and unenforceable by the landlord. Additionally, a landlord has the burden of proving reasonable efforts to re-rent the premises and mitigate damages. It may be worthwhile to have your lease and situation reviewed by an experienced landlord-tenant lawyer.
I recommend that you contact an attorney to review the specific facts of your matter and provide you a legal assessment. Please note that this response DOES NOT create an attorney-client relationship.