Wierd beeping Noise in an 06 Ls focus

[jarradgoodwin91]

hey guys!
need a bit of help!
as you can see i own an 06 ls focus!
very proud of my ride!
but recently me and my old man have been noticing a very faint beeping noise coming from under the dash when we're driving!
not all the time just every now and then!
when my old man first heard it and told me about it i thought he was talking about the seatbelt alarm or the door alarm!!
but then when i heard it it definitely wasnt either of them!
any help would be greatly appreciated!
thanks