The “default” LTspice transistor is idealized. Real ones aren’t that good :) Transistors are *called* “switches” but they are not literal switches like a toggle switch is – they are not mechanical contacts. Perhaps inadvertently, you have set up the transistor as a common-base switch, and that has a chance of working acceptably – you just need some load, the output can’t float. <!-- Begin schematic: In order to preserve an editable schematic, please don't edit this section directly. Click the "edit" link below the image in the preview instead. --> ![schematic](https://i.sstatic.net/dLSvX.png) <!-- End schematic --> The component values do depend on the parameters of the transistor, and have to be adjusted in practice. It's not the best way to implement a switch, but it certainly works well enough to be useful for something. The general idea for common-base switches is having ample amplitude of base drive. Ideally, the base drive would be a current source. Below are the input, output and control waveforms of the circuit above. The control waveform's amplitude is scaled down 50% to make it fit better in the plot. [![Plot of I/O waveforms, and the control waveform][1]][1] The non-linear distortion is about 0.5%. The input, output and distortion residue waveforms are plotted below. [![Plot of the I/O waveforms and the distortion residue while the switch is on][2]][2] A more dependable way to implement a bipolar switch would be to convert the input signal to a current, then switch the current between two resistors, and take the output from one resistor only. <!-- Begin schematic: In order to preserve an editable schematic, please don't edit this section directly. Click the "edit" link below the image in the preview instead. --> ![schematic](https://i.sstatic.net/enVOe.png) <!-- End schematic --> The switching action is clean: [![The output voltage waveform as the switch switches][3]][3] The distortion residuals are <0.1%: [![The waveform of distortion residuals][4]][4] [1]: https://i.sstatic.net/3b8An.png [2]: https://i.sstatic.net/kFEAA.png [3]: https://i.sstatic.net/mZMeu.png [4]: https://i.sstatic.net/aUPId.png