Example of selecting an edge of a mesh using a timer

bmesh_edge_selection_timer.py

import bpy
import bmesh


def select_an_edge_every_2_seconds():
    obj = bpy.context.object.data
    bm = bmesh.from_edit_mesh(obj)
    bm.edges.ensure_lookup_table()

    not_selected_edges = []
    for e in bm.edges:
        if e.select:
            e.select = False
            continue
        not_selected_edges.append(e)

    random_edge = random.choice(not_selected_edges)
    random_edge.select = True
    print("selected", random_edge.index)

    bmesh.update_edit_mesh(obj)

    return 2.0

def unregister_timer():
    print("unregistering select_an_edge_every_2_seconds timer")
    bpy.app.timers.unregister(select_an_edge_every_2_seconds)

bpy.app.timers.register(select_an_edge_every_2_seconds)
bpy.app.timers.register(unregister_timer, first_interval=20.0)