I do not expect a spike or surge issue here. But you can supply odd PWM (see google) line voltage and all bets are off about life span issues. Stop doing this and change the switch.
I purchased a Samsung led tv and i have a dimmer switch connected to where the tv us plugged in ( in other words when you lower the dimmer on the switch, it shuts off the power for the tv. ) Apparently i never knew that the switch controlled that outlet
Now here's what happened. I couple of time when i turned off the dimmer switch, i've noticed my led will randomly power off and power on ( did this about 10 times within 15 seconds ) . Luckily i had a surge protector ( a good one) for this
The tv works fine with no problems that i can see but did this shorten the life of it or its nothing too worry about ? Im thinking it may be a spike or surge

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic