No transformer needed. The 3 Volt Lithium watch style battery can replaced (#HW2300) and each will last up to 80 hours. Plan them for a spot you can easily reach to flip the switch on and off.
LED Dollhouse Lights
LED 3-Arm Frosted Down Tulip Shade Chandelier
Reported Stock: 11
Vendor: Aztec MiniaturesModel: HW2321
$48.95LED 3-Arm Silver Frosted Down Tulip Shade Chandelier
Reported Stock: 1
Vendor: Aztec MiniaturesModel: HW2360
$57.95LED 5-Arm Frosted Down Tulip Shade Chandelier
Reported Stock: 3
Vendor: Aztec MiniaturesModel: HW2323
$79.95LED Copper Large Glass Frosted Tulip Table Lamp
Reported Stock: 11
Vendor: Aztec MiniaturesModel: HW2326
$24.95LED Large Frosted Glass Tulip Ceiling Lamp
Reported Stock: 21
Vendor: Aztec MiniaturesModel: HW2312
$24.95LED Modern Hanging Lamp w/ Plastic Round Shade
Reported Stock: 1
Vendor: Handley House MiniaturesModel: HW2316
$24.95LED Old Fashioned Oil Lamp Copper Finish
Reported Stock: 12
Vendor: Aztec MiniaturesModel: HW2342
$35.95