If you're looking for lot lighting servicing, you have but to take a drive around town at night and see who needs someone with a bucket truck.
Realtors can be a good source. They are often asked who can do service work.
But nothing beats face-to-face contact with those who will need your services. Find out who they are, and go talk to them. Apartment managers, strip malls, office parks, all have a person who is responsible to calling an electrician.