Is it possible to help an elderly tenant contact social services without being his/her guardian or having power of attorney

There's nothing wrong with you making a phone call or two, especially if the family of thsi elderly person is shirking their duties to help their relative and the elderly person wants you to help.

Disclaimer: Please note that this answer does not constitute legal advice, and should not be relied on, since each state has different laws, each situation is fact specific, and it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue. This answer does not create an attorney-client relationship.

I would not say it is interfering if a person needs are and family is not willing to become involved. Anyone can, and perhaps should, contact Adult Protective Services. Such contact is help confidential. APS will likely open an investigation and try to determine how much help this person may need. If the person needs help to protect their person and or estate, and there is no other person willing to step forward, APS will recommend the County's Public Guardian to establish a Conservatorship of the Estate and/or Person.