Consult the terms of your lease. These questions of contribution towards shared utilities or common spaces is usually addressed in the terms of the contract.
If you cannot understand the terms of your lease, consult with an attorney who can help explain its terms.
Yes, if the obligation to pay the $10 is set forth in writing in the lease or rental agreement.
Frank W. Chen has been licensed to practice law in California since 1988. The information presented here is general in nature and is not intended, nor should be construed, as legal advice for a particular case. This Avvo.com posting does not create any attorney-client relationship with the author. For specific advice about your particular situation, please consult with your own attorney.
As you can see from my colleague's answers, both of wich I agree, outdoor lighting is a negotiable cost that should be contained in your written lease.
If the lease is silent, the interpretation would be that there is no additional cost to you as it would be a change in the terms of your lease. If, however, you are in a very short term lease (i.e., month to month) the landlord can give you a notice of increase in rent consistent with the notice requirements (30/60 days)
Disclaimer: I am licensed to practice law in the state of California. Therefore if your case in not in California, the information contained herein may not apply. This answer is provided as a public service and as a general response to a general question, it is not meant, and should not be relied upon as specific legal advice, nor does it create an attorney-client relationship.