Anyone know what this is for?

[blackcloud]

Does anyone know what this is for in my bedroom?

 

[Sureitsoff?]

its might supply something in the bedroom or an adjacent room if it is still in use but that pic actually tells us nothing.

 

[Mottie]

It's to switch something electrical on and off.

 

[ericmark]

It is called a switched fuse connection unit (FCU) often used for outside lights or small out buildings, and central heating supplies, but could be anything really.

 

[boringoldcodger]

In your picture it's switched off so there's a good chance it's not connected to anything (to anything that's in use?).
With the power switched off you could try opening it up and seeing if there's any input and output cables and the direction they come from, but it's scarcely worth it if everything's working alright.