Having some trouble trying to find out what this blue thing is has a fitting for a hose and to connectors for wires but isn’t connected?
An '86 or later 240 seemingly.
I haven't come across that part before, it may not be original, it looks to be a vacuum or boost switch.
Volvo 240 lh2.2 turbo 5 speed manual
IIRC it turns off the A/C at full throttle
Similar looking, but that switch is further over to the centre of the firewall
Can you see a part number and type it into DuckDuckGo or Google?
In the search type somepink like "9983258 Volvo " and see what it displays.