It appears you have to babysit their things for thirty (30) days.
From nolo.com:
After the tenant has been evicted, the landlord might find that the tenant has left behind personal property. If the tenant has informed the landlord in writing that the belongings are abandoned, then the landlord can dispose of the items immediately without any liability to the tenant. Otherwise, the landlord must wait for 30 days before disposing of the property. The landlord can either leave the property in the rental unit or remove it to a storage unit. If the tenant does not claim the property within 30 days (and pay for the costs of storage, if applicable), then the landlord can dispose of the property without any liability to the tenant (see W. Va. Code § 55-3A-3(h)).