Can someone file a lien on my property with no contract in Nevada?

In order to put a lien on someone's property, the person wanting to lien the property has to have either a statutory lien right (e.g., building contractors) or a written contractual lien right.  A "verbal contract" cannot give someone a right to lien your property.  It can obligate you to pay the $1,500 bill, but if you don't pay it then the owner can sue you in court to collect the sum.  Once someone has a judgment against you, then they have a statutory right to put a judgment lien on your property.  However, you say your are in a shopping center and most shopping centers have written, recorded agreements governing the operation of the center:  restrictive covenants (CC&Rs) and common area maintenance agreements (CAM Agreement) in which the various owners share the maintenance of the parking lots, etc.  Typically, CC&Rs and/or CAM Agreements have a provision in them that says that if one owner pays for improvements benefitting the other owners in the center, then those other owners owe their share of such costs and if they don't pay their share then a lien can be put on their property.  If your shopping center has such agreements, those agreements "run with the land" and are equivalent to you signing an agreement to let someone put a lien on your property.  If your shopping center has such agreements, then he can lien your property.