You will need to fill in all of the questions in the new N-400 including details on your past 5 years of work / school and your addresses for the past 5 years. You will also provide tax returns which will ahve your address of residence for the period. Usually that evidence is in itself enough to meet the required proof of physical presence. If more is needed, it will be usually asked for by a RFE or in the notice of interview. Good luck.
Legal disclaimer: The statement above is provided by CC Abbott is based on general assistance and not intended to be a legal opinion because not all the facts are provided. The person requesting information and all others reading the answer should retain an attorney who is permitted by the state bar within the jurisdiction who can examine the complete facts and provide a legal opinion on your case. All information provided in the above answer and other information provided by CC Abbott does not create an attorney/client relationship within any state of Federal law.
No, you don't need to show a lease. The pay stubs, bank statements, tax returns, etc. can prove your physical presence and good moral character.
PROFESSOR OF IMMIGRATION LAW for over 10 years -- This blog posting is offered for informational purposes only. It does not constitute an attorney-client relationship. Also, keep in mind that this is an INTERNET BLOG. You should not rely on anything you read here to make decisions which impact on your life. Meet with an attorney, via Skype, or in person, to obtain competent personal and professional guidance.
USCIS will be looking at your tax returns for your proof of presence. They can also look at your pays tubs, bank account statements, credit card statements, car insurance/registration and bills for your physical presence. If you are paying rent to your brother, your brother can provide you with a landlord letter.