Most obvious options:

- Use a large bottle

- Use a small lightbulb

- Construct the bottle around the lightbulb

- Construct the lightbulb inside the bottle

- Cut off and replace part of the bottle; this can be done almost seamlessly

- There's no technical reason that a lightbulb needs to be made of glass, so we can make a collapsing one, and unfold it inside like a ship-in-a-bottle