Obviously you shouldn't connect lights in series, but if you did you wouldn't cause a fire. You would just have very dim light, as the current through each bulb would be half of normal. And, the power used by each bulb would be one quarter of normal, so the bulbs would be very dim.

You're right that the light bulbs would be dimmer in series but your math is all wrong.

Current is the same at all points in a series circuit. Voltage on the other hand will be shared among the lights thus causing the lights to be dimmer.

Ok lets say there's 120Volts and you have 2 60 Watt bulbs.

Current = Power/Voltage

I = 120Watts/120Volts

I= 1Amp

This circuit will have 1 amp flowing through it.

So take one of the 60 Watt bulbs in this circuit and you want to find the voltage for that bulb.

Voltage = Power/Current

E = 60Watts/1Amp

E = 60 Volts

As you can see, each bulbs only gets 60Volts per light bulb. (Dimmer Lights)

Power rating will be the same.

A light bulb rated at 60 Watts will continue to be 60 Watts.

Power = Voltage * Current

P = 60Volts * 1Amp

P = 60 Watts

Ok, now for parallel.

Voltage is the same in a parallel circuit so each light bulb with the same wattage rating will have the same intensity.

Current = Power/Voltage

I = 60Watts/120VAC

I= .5 Amp

So each light will get half an Amp and receive 120V. Current for this circuit is still at 1 Amp if you have 2 60 watt bulbs in parallel. The same as in series.

Power = Voltage/Current

P = 120V/.5Amp

P = 60 Watts

Power is the same per light bulb as in series.

The difference is that voltage is halved with a series circuit.

Add too many lights without increasing the gauge of wire and yes you'll have a fire. Just make sure you have the proper gauge for the current you'll be using.

You'll see an increase in current with added lights.

Current = Power/Voltage

1 60 Watt bulb

I = 60Watts/120Volts

I = .5 Amps

2 60 Watt bulbs

I = 120Watts/120Volts

I = 1 Amp

3 60 Watt bulbs

I = 180Watts/120Volts

I = 1.5 Amps

Sorry Hoppy, Couldn't help myself. :mrgreen: