Depends on your request. Frequency, amplitude (voltage), power (current), what control, volume requirements, electromagnetic radiation, is that two signal switching, or more... Square wave and sine wave difference is not very big, but wiring inductance and distributed capacitance, will cause the waveform distortion, especially when high frequency. Can use MOS switch, switch, such as 4051405, 2405, 3, but the voltage cannot be higher than the device allows, but also on resistance, can use the relay switching frequency requirements, but volume is larger, a longer lead. High frequency rf switch can have. But if small power voltage, electric current is big, can design their own MOS switch tube, can reach more than a few hundred volts, more than hundreds of Ann.