Welcome
@David Johnson. The older vans came with lights very similar to your roof mounted lights but they had plastic clips on the them to attach them to you bed end roof support, know as the hockey stick. The lights have their own on and off switch and plugged via a curly cable into that "head phone" jack in the adjacent light
The more recent camper and Expandas come with a similar setup, but its a fan light combo, but still attaches to the hockey stick.
The older ones are around $30 and are still available
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and the newer ones around $65
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We have a roof light under the overhead cabinet adjacent to the bed anyway, and initially I thought the same as
@relgate regarding the fan and just left it the cupboard. Princess Crusty found it one balmy evening, attached it to the hockey stick and turned it on. We both were pretty impressed with it and we used regularly, but as
@relgate said I think if the van didn't come with it I wouldn't be buying one, and for $65 I likely spend another $60 and opt up to the 12v Sirocco fan because its very efficient and quieter. We don't require a light in the bed, but the kids might find it useful.