Have your attorney draft a letter to them stating any damage will be deducted from their security deposit and if there are cost overruns, you have authorized your attorney to file suit against them.

Clean the place up and start fresh with a tenant that is properly screened, paying market rent, and respecting your authority as the owner.Another thought: you may want to consider a property manager.

It can also go even deeper -- what if the loan AND the servicing are BOTH sold, BUT the original lender authorizes the loan servicer to use their trademark and branding, and authorizes the 1-800 number employees to answer the phone as if they were Wells Fargo employees?

I bought a lease option a couple years back.I signed a lease with the owner that gave me full authority - and full responsibility - for the property.

Recently I've tried sending a certified letter (containing all my contact info and a request for contact) with return receipt, but USPS reports they were unable to deliver it  - Notice Left (No Authorized Recipient Available)There is nothing particularly wrong, and she's completely current with rent based on auto-payments.I feel uncomfortable not being able to reach her.

My lease also says I am authorized to show it to potential buyers or renters with proper notice.Some tenants fight this and I typically let it go because I know they'll sabotage any showings anyway.

New tenants are not authorized unless they go through me with an application.

I would have had the seller sign a 3rd party authorization and limited power of attorney when we closed on the sale.

Will all partners have full authority? 

It's called the Federal HOUSING Authority, not Federal INVESTMENT Authority.