Group of entities from different domains

Is there a way to group entities from differing domains? e.g.
my bedroom has two lifx bulbs (light.xxxx_lamp)
and an overhead controlled by a Shelly relay (switch.shelly_25_channel_1)

They all control lights with states of on/off.
How do I group them?

Create a helper, ‘switch as x’. Select the switch, it will create a new light entity, hide the switch (it might do that anyway), put the new light in the group.