It is possible to replay CAN bus messages for building intercom system?
Canbus is not normally single wire, equally the voltage makes it seem more like K-line / L-line, if that is the case you should be able to hook it up to a PC serial port and log it at 10400 baud, (CANbus is usually too fast for reliable single wire transfer over the kind of distances a home intercom would work at)

It is 100% possible to replay messages, just in this case depends a little on the implementation, e.g. if it uses some kind of rolling code (unlikely) to prevent replay messages from being valid.

Have a look at where that data pin connects to inside the device, usually there will be a little 8 pin IC that acts as a tranciver for the data bus, this should give you a very solid tell tale of exactly what physical layer it is using (could alternatively just be a transistor), 

And finally, if it is K-line, you will need to offset the voltage of any logic analyser you may hook up to it at a later stage, low is below 33% of VCC, and high is above 66%, so for your 14.5V bus you want to offset near the middle for reliable capture from some of the weirder devices. 

Edit: Adding image of suggested transceiver schematic.