Does it shed light on seances? (10)

I believe the answer is:

spiritlamp

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'does it shed' is the definition.
I know nothing about this answer so I can't tell whether this works.

'light on seances?' is the wordplay.
'light' becomes 'lamp' (lamp is a kind of light).
'on' means one lot of letters go next to another.
'seances?' becomes 'spirit' (I can't justify this - if you can you should believe this answer much more).
'lamp' after 'spirit' is 'SPIRITLAMP'.

Can you help me to learn more?

I've seen this clue in The Irish Independent.

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