input: from typing import List
  
  def generate_voltage_signal_with_noise(frequency: float, amplitude: float, noise_std_dev: float) -> List[float]:
      """ Generate a voltage signal with a given frequency and amplitude, and add random noise to it.
      >>> generate_voltage_signal_with_noise(250, 1, 0.1)
      [...]
      """
output:     import numpy as np
      import math
  
      num_samples = 1000
      time_step = 1.0 / num_samples
      time_array = np.arange(0, 1, time_step)
  
      signal = amplitude * np.sin(2 * math.pi * frequency * time_array)
      noise = np.random.normal(0, noise_std_dev, num_samples)
  
      noisy_signal = signal + noise
  
      return noisy_signal.tolist()