Electrical - Light String
https://www.harborfreight.com/24-ft-12-bulb-outdoor-string-lights-63483.html $20 for 12 sockets. Includes incandescent bulbs but can replace with LED;
Outdoor String Lights by Deneve - Heavy Duty Hanging Market Patio Cafe Pergola Rope String Backyard Lights Pro Weatherproof Commercial Quality Bistro Umbrella Festoon Garden Lights 48 Feet Long (Bulbs Not Included)
https://www.amazon.com/gp/product/B00J4CUO3S/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1 $44.95 for 15 sockets 3' apart. $39.95 on sale
Search on Amazon for "Light string".
https://www.amazon.com/String-Light-Company-Commercial-Suspended/dp/B004EWFXMU $27.20 when on sale
Use 1" conduit clamps to hold each bulb.