I just heard back from one of our experts and they recommend the following:
If the lighter still has butane fluid in it then it needs to safely be removed and disposed of. So not around any sources of ignition. A fume hood would be preferable if being done in a museum. If it is difficult to do, you can look into taking it to a cigar shop and asking them to drain the butane and remove the wick. You should let both the wick and the lighter continue to evaporate off any residual butane for a few days in a fume hood. Then when the odor is completely gone you can put the wick back in and store the lighter with the rest of the collections.
I hope this answers your question.