I have some gas lanterns that are hooked to light switch. I was wondering if there is anyway I could add some type of timer to it, so I could set them up to just run a few hours each day?
I forgot to add that I would also like to be able to control the switch manually not just by timer.
There are several on the market. Hop over to Amazon and search for "light switch timer" to get an idea.
Note that some of them require a neutral so check to see if your current switch has a neutral or is a switchleg without a neutral. It will influence your choice.
Note, there are two kinds of timers (often identical in outward appearance). Some are approved for incandescent (resistive) loads only. These typically use a semiconductor (TRIAC) switch. Others are good for assorted loads (fluorescent, etc...) as they use a motorized mechanical switch inside. This is what you want.
Many of the "time of day" type of timer (as opposed to the count down kind) use a battery to run the timer parts so they don't rely on a neutral at the switch (which older installations may not have).