NO THEY DON'T
The two Blacks are neutrals. These wires should be joined together using a section of terminal strip. Do not insert either of these wires in any of the switch terminals.
The incoming red goes to Com. (Permanent live)
The outgoing red goes into L1 (switched live)
L2 remains unused because you do not have 2 way switching in your bathroom.
Cledlyn
September 2008