Landlord-tenant — Eviction — Judgment — Vacation — Where service of eviction complaint on tenants was made by substitute service on person who was not co-resident or family member of tenants but who was occupying premises that tenants had vacated, tenants were not properly served and judgment for possession is void — Further, landlord who knew that tenants had vacated premises knowingly and intentionally misrepresented material facts in eviction complaint — Judgment is vacated, complaint is dismissed and ruling on sanctions is reserved