Can I lay an attic floor over electrical wires?
If you have wires/cables that run across the top of the attic floor joists, you could build up the joist with ripped 2x4's that would provide another 1-1/2 inch clearance above the joists for the wires.  You would have to provide a gap between the added sections of wood to provide a channel for the wires to lay in.  Or lay 2x4's flat perpendicular to the joists, running parallel to the wires.  Then lay your attic floor down on the new 2x4's.

EDIT1:

One other thing to consider is you probably want to provide protection for any of the wires that end up under the flooring.  Might want to put nailing plates over the wires so that an errant nail doesn't find its way into a wire.