Joseph said she knew nothing about the knife but that the man living in the garage often came into the premises when she was not there.
"Regardless of the behaviour of the extra person at the premises or any incidents associated with him, Miss Joseph has breached her agreement by allowing him to live there," Lang wrote.
It was not acceptable to have someone living in a garage, the adjudicator wrote.
Joseph had also had another person living on the property earlier last year, according to a Tenancy Tribunal finding.
"I am satisfied that Property Brokers made Miss Joseph and her support workers aware that she was not able to have someone else live at the premises under the terms of her agreement," Lang wrote.
"That means Miss Joseph was aware she was not able to have any one else also live at the premises when she invited the man to live in her garage."
Lang was satisfied that even if the man left the property, Joseph would get someone else to live in the garage.
According to the Residential Tenancies Act 1986, where a tenant breaches their tenancy agreement but the breach can be remedied, the landlord must first serve the tenant a notice to remedy the breach within 14 days.
Property Brokers had served Joseph with a 14-day notice on December 2, but the man did not stop living in the garage, Lang wrote.
The landlord wanted Joseph to be evicted immediately but Lang gave her two weeks' notice due to health issues, adding that she had support via a number of organisations who could help her leave the house by the deadline of January 28.